Safety Standard for Residential Gas Furnaces and Boilers, 73272-73293 [2023-23302]

Agencies

• Consumer Product Safety Commission

[Federal Register Volume 88, Number 205 (Wednesday, October 25, 2023)]
[Proposed Rules]
[Pages 73272-73293]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2023-23302]


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CONSUMER PRODUCT SAFETY COMMISSION

16 CFR Part 1408

[CPSC Docket No. CPSC-2019-0020]


Safety Standard for Residential Gas Furnaces and Boilers

AGENCY: Consumer Product Safety Commission.

ACTION: Notice of proposed rulemaking; notice of opportunity for oral 
presentation of comments.

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SUMMARY: The U.S. Consumer Product Safety Commission (Commission or 
CPSC) has determined preliminarily that there is an unreasonable risk 
of injury and death associated with residential gas fired central 
furnaces, boilers, wall furnaces, and floor furnaces (gas furnaces and 
boilers). To address this risk, the Commission proposes a rule to 
detect and prevent dangerous levels of carbon monoxide (CO) production 
and leakage from residential gas furnaces and boilers. The Commission 
is providing an opportunity for interested parties to present written 
and oral comments on this notice of proposed rulemaking (NPR).

DATES: Deadline for Written Comments: Written comments must be received 
by December 26, 2023.
    Deadline for Request to Present Oral Comments: Any person 
interested in making an oral presentation must send an email indicating 
this intent to the Office of the Secretary at [email protected] by 
December 26, 2023.

ADDRESSES: 
    Written Comments: Comments related to the Paperwork Reduction Act 
aspects of the proposed rule should be directed to the Office of 
Information and Regulatory Affairs, OMB, Attn: CPSC Desk Officer, FAX: 
202-395-6974, or emailed to [email protected].
    Other written comments in response to the proposed rule, identified 
by Docket No. CPSC-2019-0020, may be submitted by any of the following 
methods:
    Electronic Submissions: Submit electronic comments to the Federal 
eRulemaking Portal at: www.regulations.gov. Follow the instructions for 
submitting comments. CPSC typically does not accept comments submitted 
by email, except as described below. CPSC encourages you to submit 
electronic comments by using the Federal eRulemaking Portal, as 
described above.
    Mail/hand delivery/courier Written Submissions: Submit comments by 
mail/hand delivery/courier to: Office of the Secretary, Consumer 
Product Safety Commission, 4330 East West Highway, Bethesda, MD 20814; 
telephone: (301) 504-7479. If you wish to submit confidential business 
information, trade secret information, or other sensitive or protected 
information that you do not want to be available to the public, you may 
submit such comments by mail, hand delivery, courier, or you may email 
them to: [email protected].
    Instructions: All submissions must include the agency name and 
docket number. CPSC may post all comments without change, including any 
personal identifiers, contact information, or other personal 
information provided to: www.regulations.gov. Do not submit through 
this website: confidential business information, trade secret 
information, or other sensitive or protected information that you do 
not want to be available to the public. If you wish to submit such 
information, please submit it according to the instructions for mail/
hand delivery/courier written submissions.
    Docket for NPR: For access to the docket to read background 
documents or comments received, go to: www.regulations.gov, insert the 
docket number CPSC-2019-0020 into the ``Search'' box, and follow the 
prompts.

FOR FURTHER INFORMATION CONTACT: Ronald A. Jordan, Directorate for 
Engineering Sciences, Mechanical

[[Page 73273]]

Engineering, Consumer Product Safety Commission, National Product 
Testing and Evaluation Center, 5 Research Place, Rockville, MD 20850; 
telephone: 301-987-2219; [email protected].

SUPPLEMENTARY INFORMATION:

I. Background

    On August 19, 2019, the Commission published an advance notice of 
proposed rulemaking (ANPR) to develop a rule to address the risk of 
injury associated with residential gas furnaces and boilers from CO 
production and leakage. 84 FR 42847. The Commission received 15 
comments. The Commission is now proceeding with this proposed 
rulemaking.\1\ The information discussed in this preamble is derived 
from CPSC the Staff Briefing Package for the NPR, which is available on 
CPSC's website at: https://www.cpsc.gov/s3fs-public/Notice-of-Proposed-Rulemaking-Safety-Standard-for-Residential-Gas-Furnaces-and-Boilers-COMBINED-PDFS.pdf?VersionId=7BJ3c6EeDF78nHorx2mCEr94XygwgeQV.
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    \1\ The Commission voted (4-0) to publish this notice of 
proposed rulemaking as drafted. Commissioner Feldman issued a 
statement in connection with his vote, available at: https://www.cpsc.gov/s3fs-public/Comm-Mtg-Min-Infant-Rockers-NPR-and-Gas-Furnaces-and-Boilers-NPR.pdf?VersionId=8Ct.NBI7RhSXyozTJBE65q3lCSyU_aMl.
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II. Statutory Authority

    This rulemaking falls under the authority of the CPSA, (Consumer 
Product Safety Act) 15 U.S.C. 2051-2089. Section 7(a) of the CPSA 
authorizes the Commission to promulgate a mandatory consumer product 
safety standard that sets forth performance or labeling requirements 
for a consumer product, if such requirements are reasonably necessary 
to prevent or reduce an unreasonable risk of injury. 15 U.S.C. 2056(a). 
Section 9 of the CPSA specifies the procedure that the Commission must 
follow to issue a consumer product safety standard under section 7 of 
the CPSA. In accordance with section 9, the Commission commenced this 
rulemaking by issuing an ANPR.
    According to section 9(f)(1) of the CPSA, before promulgating a 
consumer product safety rule, the Commission must consider, and make 
appropriate findings to be included in the rule, on the following 
issues:
    (A) The degree and nature of the risk of injury that the rule is 
designed to eliminate or reduce;
    (B) the approximate number of consumer products, or types or 
classes of product, subject to the rule;
    (C) the need of the public for the products subject to the rule and 
the probable effect the rule will have on utility, cost, or 
availability of such products; and
    (D) the means to achieve the objective of the rule while minimizing 
adverse effects on competition, manufacturing, and commercial practices 
consistent with public health and safety.

15 U.S.C. 2058(f)(1).
    Under section 9(f)(3) of the CPSA, to issue a final rule, the 
Commission must find that the rule is ``reasonably necessary to 
eliminate or reduce an unreasonable risk of injury associated with such 
product'' and that issuing the rule is in the public interest. 15 
U.S.C. 2058(f)(3)(A) and (B). Additionally, if a voluntary standard 
addressing the risk of injury has been adopted and implemented, the 
Commission must find that:
     The voluntary standard is not likely to eliminate or 
adequately reduce the risk of injury, or
     substantial compliance with the voluntary standard is 
unlikely.

15 U.S.C. 2058(f)(3)(D). The Commission also must find that expected 
benefits of the rule bear a reasonable relationship to its costs and 
that the rule imposes the least burdensome requirements that would 
adequately reduce the risk of injury. 15 U.S.C. 2058(f)(3)(E) and (F).

III. The Product

    Central furnaces, boilers, wall furnaces, and floor furnaces fueled 
by natural gas or propane (gas furnaces and boilers) are used to heat 
all categories of consumer dwellings. These products burn a mixture of 
gas and air within the combustion chamber of a heat exchanger. As the 
mixture of fuel and air is burned, heat is released and transferred 
through the wall of the heat exchanger to the medium surrounding the 
heat exchanger and circulated through air ducts (for central furnaces), 
water pipes throughout the dwelling (for boilers), or directly into the 
ambient air to provide heat (for wall furnaces and floor furnaces).
    Burning the mixture of fuel and air results in the formation of 
combustion products that are typically composed of oxygen, carbon 
dioxide, water vapor, and CO. The combustion products are exhausted to 
the outdoors through a vent system, either vertically through the roof 
or horizontally through a side wall through the vent pipe. When the 
mixture of fuel and air is burned completely, the concentration of CO 
produced should remain relatively low. However, when issues arise with 
the combustion process (such as fuel-air mixtures that are not 
optimal), dangerous levels of CO can be produced. The combination of 
production of dangerous levels of CO during the combustion process and 
leakage of that CO through the vent system into the living space is a 
potentially deadly hazard pattern identified by CPSC staff.
    In a gas-fired central furnace (Figure 1), air is the medium that 
surrounds and is heated by the heat exchanger. A large fan is used to 
force-circulate the heated air across the exterior surfaces of the heat 
exchanger, through a duct system, and then the heated air exits the 
duct system through warm air registers typically within the dwelling. 
The arrow in Figure 1 depicts the vent pipe.
    In a gas boiler (Figure 2), water or steam is the medium that 
surrounds and is heated by the heat exchanger. The heated water or 
steam is circulated, using a pump to force the fluid through a piping 
system to radiators typically in each room in the dwelling. Living 
areas are heated through radiative and conductive heat transfer from 
the heated water or steam supplied to the radiators to the room. Gas-
fired central furnaces and boilers are considered central heating 
appliances because they provide heat to each room of a dwelling. The 
arrow in Figure 2 points to the boiler's vent pipe.

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[GRAPHIC] [TIFF OMITTED] TP25OC23.003

    In addition to central gas-fired furnaces and boilers, the proposed 
scope of the NPR also includes gas wall furnaces (Figure 3) and gas 
floor furnaces (Figure 4). As their names indicate, gas wall furnaces 
are installed in wall spaces, typically between the wall stud framing 
members; and floor furnaces are installed in the floor, typically 
between the floor joist framing members. Wall furnaces and floor 
furnaces provide localized heating directly to the room in which they 
are located, and indirectly to adjoining rooms within the dwelling. The 
combustion products of wall furnaces are vented to the outdoors, either 
vertically through the roof, or horizontally through a side wall with 
the vent pipe running along the length of the wall studs between which 
the unit is installed. The combustion products of a floor furnace are 
typically vented horizontally through a side wall, with the vent pipe 
running along the length of the floor joists between which the unit is 
installed and through an exterior wall.
[GRAPHIC] [TIFF OMITTED] TP25OC23.004


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IV. Risk of Injury

A. Incident Data

1. Fatalities
    From the time period of 2017 to 2019 (the most recent period for 
which data are complete), there were annually an estimated 21 CO-
related deaths associated with gas furnaces and boilers (burning 
liquefied petroleum, natural gas, and unspecified gas).\2\ For the 20-
year period, 2000 through 2019, these products were associated with a 
total of 539 deaths from CO poisoning. Tab A of the Staff NPR Briefing 
Package provides further information regarding fatalities.
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    \2\ Non-Fire Carbon Monoxide Deaths Associated with the Use of 
Consumer Products 2019 Annual Estimates. J. Topping. CPSC 
Directorate for Epidemiology. March 2023. https://www.cpsc.gov/s3fs-public/NonFireCarbonMonoxideDeathsAssociatedwiththeUseofConsumerProducts2019AnnualEstimates.pdf?VersionId=90WCZoH61aVUrTgDtOo16LLKZf1EeH3E.
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2. Injury Estimates
    To estimate the number of injuries associated with CO exposure from 
natural gas and propane furnaces and boilers, an interdisciplinary team 
of CPSC staff evaluated injuries reported through the National 
Electronic Injury Surveillance System (NEISS) (See Tab J of the Staff 
NPR Briefing Package). Staff queried NEISS for data between the years 
2014 and 2018. Staff identified 236 nonfatal injuries related to CO 
leakages from gas furnaces and boilers that occurred during this 
period. Of the 236 nonfatal injuries, 18 resulted in hospital 
admissions via the emergency department (ED), and 218 were treated in 
the ED and released. Staff used NEISS incidents and the Injury Cost 
Model (ICM) to extrapolate and generate national estimates for injuries 
from CO leakages from gas furnaces and boilers treated in EDs and other 
settings. Staff, using the ICM, calculated that the aggregate number of 
nonfatal injuries from CO leakages from gas furnaces and boilers from 
2014 to 2018 was 30,587. Staff estimated that of the 30,587 injuries, 
22,817 were treated in an outpatient setting (e.g., doctor's office, or 
clinic), 7,358 resulted in ED treatment, 333 resulted in hospital 
admissions via the ED, and 79 resulted in direct hospital admissions.

B. Description of Hazard--Acute CO Poisoning

    In Tab C of the Staff ANPR Briefing Package \3\ staff described the 
hazard pattern for CO poisoning associated with gas furnaces and 
boilers; which involves (1) hazardous levels of CO from incomplete 
combustion of the source fuel/gas and (2) exhaust leakage of that 
hazardous CO into the living space through a leak in the exhaust vent 
system. Staff's review of the 83 incidents, in conjunction with 
findings from earlier in-depth investigation (IDI) reviews, identified 
the following factors related to the incomplete combustion and exhaust 
leakage hazard patterns.
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    \3\ Draft Advance Notice of Proposed Rulemaking: Performance 
Requirements for Residential Gas Furnaces and Boilers. Retrieved at: 
https://cpsc.gov/s3fs-public/Draft%20ANPR%20-%20Performance%20Requirements%20for%20Residential%20Gas%20Furnaces%20and%20Boilers.pdf.
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1. Production of Dangerous Levels of CO From Incomplete Combustion
    Complete combustion of hydrocarbon fuels, such as natural gas or 
liquefied petroleum gas (LP-gas or propane), requires a proper mixture 
of air and fuel, as well as an adequate amount of heat to ignite the 
combustion air-fuel mixture. Incomplete combustion of the fuel supplied 
to gas appliances can lead to production of hazardous levels of CO. 
Incomplete combustion can occur when there is inadequate combustion of 
air (for instance when air openings to the appliance combustion chamber 
or burner assembly, or the exhaust outlet from the appliance is 
blocked); too much fuel is supplied to the appliance burner (i.e., 
over-firing); or the burner flame temperature falls below the ignition 
temperature of the combustion air-fuel mixture (i.e., flame quenching). 
Depending on the severity and duration, all these conditions can result 
in incomplete combustion of the fuel; which, in turn, can result in the 
gas furnace or boiler producing dangerous levels of CO. Staff's ongoing 
review of IDIs confirms that these hazard patterns have not changed 
since the publication of the ANPR.
2. Exhaust Leakage
    Combustion products produced by a gas furnace or boiler are 
normally vented to remove them from the home through a properly 
functioning vent system. A potential CO hazard in a home can arise if 
the combustion system of a gas furnace or boiler malfunctions and 
produces hazardous levels of CO, which a compromised exhaust system 
then allows to leak into the occupied space of the home. Typical 
exhaust failure leakage paths include a totally or partially blocked 
vent, chimney, heat exchanger, or a disconnected or hole in the vent 
pipe.
    Another potential leakage mechanism occurs when an exhaust fan or 
fireplace is installed near a gas furnace or boiler. The operation of 
an exhaust fan or a warm chimney created by a fireplace can pull air 
out of the room in which the gas furnace or boiler is installed. This 
can depressurize the room, resulting in reverse flow of the combustion 
products through the gas furnace or boiler vent system or flue 
passageways. Instead of being vented safely to the outdoors, 
depressurization can cause CO to spill into the living space. Other 
mechanisms that can lead to spillage include venting that is inadequate 
for the gas furnace or boiler connected to it. This can be caused by 
total or partial vent blockage, installation of a vent pipe that is too 
small for the gas furnace or boiler, or the connection of too many 
appliances to the vent.

V. Assessment of Relevant Existing Voluntary Standards

A. U.S. Voluntary Standards

1. Description of Existing U.S. Voluntary Standards for Gas Furnaces 
and Boilers
    In the United States, the four types of gas furnaces and boilers 
within the scope of the proposed rule are covered by the following ANSI 
Z21 voluntary standards:
     ANSI Z21.13-2022, Standard for Gas-fired low pressure 
steam and hot water boilers: This standard specifies construction and 
performance requirements for gas-fired, low-pressure steam and hot 
water boilers with input ratings of less than 12,500,000 Btu/hr (3,663 
kW). The first edition of the standard was published in 1934, and the 
standard has been revised several times, with the latest edition 
published in 2022.
     ANSI Z21.47-2021, Standard for Gas-fired central furnaces: 
This standard specifies construction and performance requirements for 
gas-fired central furnaces with input ratings up to and including 
400,000 Btu/hr (117 kW) for installation in residential, commercial, 
and industrial structures including furnaces for direct vent, 
recreational vehicle, outdoor, and manufactured (mobile) homes. The 
requirements for gas-fired central furnaces were initially included in 
ANSI Z21.13, before becoming a separate standard in 1964. From 1978 
through 1993, a separate standard for direct vent central furnaces 
(ANSI Z21.64) was in place before being consolidated into a single 
standard and harmonized with Canadian standard requirements in 1993, 
with the latest edition of ANSI Z21.47 published in 2021.
     ANSI Z21.86-2016, Standard for Vented gas-fired space 
heating

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appliances: This standard specifies construction and performance 
requirements for vented gas-fired space heating appliances with input 
ratings up to and including 400,000 Btu/hr (117 kW), including gravity 
and fan type direct-vent wall furnaces and gravity and fan-type floor 
furnaces. The ANSI Z21.86 standard was first published in 1998, with 
the latest edition published in 2016.
    All three ANSI standards have the following relevant requirements 
for gas furnaces and boilers:
     must not produce CO in excess of 400 ppm (under prescribed 
laboratory test conditions);
     shut off when vent or flue is fully blocked;
     shut off when blower door is not sealed properly (gas-
fired central furnaces only); and
     shut off if flames issue outside of the burner 
compartment.
2. CPSC Voluntary Standards Activity
    In 2000, CPSC staff proposed voluntary standard provisions that 
would require a gas furnace (ANSI Z21/83 Technical Committee 
subsequently extended the consideration of the proposed standards 
provisions to all vented heating appliances including boilers):
     to shut down if the vent pipe became disconnected; and
     to shut down if the vent pipe became totally or partially 
blocked; or
     to have a means to prevent CO emissions from exceeding the 
standard limits once installed in the field; and
     to have a means, once installed in the field, to shut down 
if CO emissions exceeded the standard limits.
    In 2002, the ANSI Z21/83 Technical Committee (TC) established a 
working group to evaluate the feasibility of using CO and combustion 
sensor technology to implement CPSC staff's CO shutoff/response 
proposal. CPSC staff participated in that working group from 2002 
through 2005. ANSI disbanded this working group in 2005 because 
manufacturers expressed concerns that there were no sensors 
commercially available that had the durability or longevity to operate 
within a gas furnace or boiler for their expected 20-year lifespan. 
CPSC staff conducted additional sensor testing from 2007 to 2008 to 
evaluate and assess the ANSI ZS21/83 TC's and working group's concerns.
    In 2014, the Commission published a request for information (79 FR 
21442) and hosted a Carbon Monoxide/Combustion Sensor Forum to gather 
more information on the availability and feasibility of CO and 
combustion sensors for use in gas furnaces and boilers.
    In 2015, the Z21/83 TC established another working group to 
evaluate a new CPSC staff proposal to add performance requirements for 
CO Shutoff/Reponses to the voluntary standards for gas-fired central 
furnaces and, boilers, wall furnaces, and floor furnaces. The Z21/83 
Technical Committee assessed that the technology required to meet the 
performance requirements was not feasible. The working group disbanded 
in 2019 without proposing any revisions to the voluntary standard that 
would adequately mitigate the CO hazard associated with gas furnaces 
and boilers.
    In Tab D of the 2019 Staff ANPR Briefing Package, staff analyzed 
the three ANSI voluntary standards and concluded that none of the 
existing voluntary standards included requirements to protect against 
many of the known failure modes or conditions that have been associated 
with production and leakage of CO into living spaces. Since publication 
of the ANPR in August 2019, none of the existing ANSI voluntary 
standards discussed above have been revised to address the known 
failure modes or conditions associated with CO poisoning, such as 
disconnection, breach, or partial blocking of flues, vents, and 
chimneys.

B. International Standards

    Existing Japanese and European gas appliance voluntary standards 
include CO shutoff or combustion control \4\ requirements, with 
reliance on gas sensing technologies to implement those standards' 
requirements.
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    \4\ Combustion control refers to a means to control the 
combustion of a gas/air mixture to ensure complete combustion of the 
gas/air mixture and to limit the production of carbon monoxide.
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1. Japan
    The primary gas heating appliances used in Japan are gas water 
heaters, gas boilers, and gas space heaters. Based on staff's review of 
the Japanese gas appliance market, instantaneous tankless gas water 
heaters \5\ (Figure 6) are more common than traditional gas water 
heaters with storage tanks.
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    \5\ Instantaneous tankless gas water heaters provide heated 
water on demand and therefore, do not require the use of a large 
storage tank, whereas traditional gas storage water heaters include 
a large storage tank used to store heated water.

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[GRAPHIC] [TIFF OMITTED] TP25OC23.005

    The governing voluntary performance and safety standards in Japan 
are:
     JIS-S-2109--Gas-burning water heaters for domestic use;
     JIS S 2112--Gas hydronic \6\ heating appliances for 
domestic use; and
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    \6\ ``Hydronic'' denotes a cooling or heating system in which 
heat is transported using circulating water. A boiler is a type of 
appliance that provides this capability.
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     JIS S 2122--Gas-burning space heaters for domestic use.
    These Japanese Industrial Standards (JIS) have explicit performance 
requirements for vented gas water heaters, gas boilers, and gas space 
heaters that require shutoff of the appliance in response to CO levels 
above a certain threshold (i.e., 300 ppm CO). The CO detection 
strategies Japanese manufacturers use to comply with JIS include 
detection of CO within the combustion chamber of the appliance and 
shutoff or combustion control in response to detection of hazardous 
levels of CO.
2. Europe
    The relevant Committee for European Standardization (CEN) standards 
for residential gas boilers (depicted in Figure 7 below) are:
     EN 15502-1, Gas-fired heating boilers, Part 1: General 
requirements and tests;
     EN 15502-2-1, Gas-fired central heating boilers, Part 2-1: 
Specific standard for type C appliances and type B2, B3 and B5 
appliances of a nominal heat input not exceeding 1 000 kW; and
     EN 15502-2-2, Gas-fired central heating boilers, Part 2-2: 
Specific standard for type B1 appliances.
[GRAPHIC] [TIFF OMITTED] TP25OC23.006

    These CEN standards include explicit performance requirements for 
gas boilers to either shut down before the CO concentration inside the 
flue exceeds 2,000 ppm or not start if the CO concentration exceeds 
1,000 ppm.

C. Staff Assessment of Voluntary Standards

    Based on staff's analysis of the relevant ANSI standards, staff 
concludes that the current ANSI Z21.13-2022, ANSI Z21.47-2021, and ANSI 
Z21.86-2016 standards do not contain performance requirements to 
protect against the known failure modes or conditions identified by the 
Commission. Specifically, the current ANSI standards lack requirements 
(1) that protect against known conditions that cause or contribute to 
CO exposure and (2) for the appliance to monitor and manage CO 
production to prevent the introduction of hazardous levels of CO in the 
appliance's exhaust vent system. Currently, deaths and injuries can and 
do occur from CO poisoning even when the furnace or boiler complies 
with all applicable existing voluntary standards in the U.S. Based on 
the above discussion and the analysis in the Staff NPR Briefing 
Package, the Commission concludes that the existing ANSI standards for 
gas furnaces and boilers are inadequate to address the hazards 
identified by CPSC.
    In addition, staff has researched international standards that 
required the same or similar performance requirements as staff's 2000 
and 2015 proposals to the Z21/83 Technical Committee. Staff identified 
several gas-sensing technologies that were being used for CO shutoff or 
combustion control of residential gas appliances used in Japan and 
Europe to correspond with the respective standards. The CO-detection 
strategies used by Japanese manufacturers include detection of CO 
within the combustion chamber of the appliance and shutoff or 
combustion control in response.
    In Europe, residential gas boilers are required to meet certain 
European combustion-efficiency requirements, as well as CO safety 
requirements. The combustion-control strategies used by European gas 
boiler manufacturers to comply with the standards are often 
accomplished by monitoring the gas/air mixture, the combustion flame, 
or the concentration of CO, oxygen, or carbon dioxide within the 
combustion products. The combustion-control strategies are also used to 
detect CO, but rather than causing shut-down of the

[[Page 73278]]

appliance, CO production is either prevented or limited by modulating 
the appliance's operation. The Japanese and European standards do not 
specify a minimum lifespan for sensing devices used to implement their 
respective CO safety and combustion efficiency requirements. However, 
adoption of the European and Japanese standards for U.S. gas furnaces 
and boilers would not be appropriate because of the design differences 
between European and Japanese products and U.S. gas furnaces and 
boilers, as well as the different regulations and standards 
requirements (other than CO safety related requirements) that European 
and Japanese appliances are required to comply with that would not 
apply to appliances made and sold in the U.S.

VI. Technical Justification for the Proposed Performance Requirements

A. Testing and Evaluation Conducted by Contractors

    Tab C of the Staff NPR Briefing Package includes links to the 
contractor reports regarding the research and testing conducted to 
assist in developing staff's proposed mandatory performance 
requirements. In 2019, a CPSC contract was awarded to Guidehouse 
(formerly Navigant, Inc.) to study the impact of CO/combustion sensors 
used in residential gas boilers and water heaters in Europe and Japan 
and to gain a better understanding of the use of CO sensors in gas 
appliances in other parts of the world and their impact in mitigating 
CO risks associated with gas appliances. This contract work was also 
was commissioned to assess industry concerns about the feasibility of 
using sensors in the exhaust flue of gas furnaces and boilers. Work on 
this contract concluded in 2021 and the findings are documented in a 
contractor report titled, ``Review of Combustion Control and Carbon 
Monoxide Sensors in Europe and Japan,'' dated June 28, 2021. The 
Guidehouse report is included as attachment 3 of Tab C of the staff NPR 
Briefing Package.
    The Guidehouse report found that in Europe, gas appliance safety is 
governed by European Union (EU) Regulation 2016/426 on appliances 
burning gaseous fuels, and compliance with the applicable standard 
published by the CEN is generally considered a means to demonstrate 
compliance with the regulation. In Japan, the Gas Business Act and the 
Act on the Securing of Safety and the Optimization of Transaction of 
Liquefied Petroleum Gas require that a manufacturer or importer ensure 
that the gas-fired equipment conforms to the technical standards 
established by an Ordinance of the Ministry of Economy, Trade and 
Industry (METI). European and Japanese manufacturers limit CO 
production with combustion safety systems, combustion control systems, 
direct CO sensing in the exhaust path, or a combination of these 
approaches. The available data revealed that CO deaths and injuries in 
the EU and Japan were declining. However, the Guidehouse report noted 
that additional factors, such as other CO alarm usage and education and 
market changes, likely played a role in these reductions of CO deaths 
and injuries as well.
    The Guidehouse report also found the designs used in U.S. 
residential heating and water heating appliances differ significantly 
from those used in Japan and Europe. In Europe and Japan, gas boilers 
are commonly used for space heating and the market has transitioned 
almost entirely to condensing systems that utilize premix power 
burners. The Guidehouse report also found that appliances with design 
platforms based on premix power burners are better suited to 
incorporate combustion control because they typically have a single 
burner, a single heat exchanger cell, and a single flame ionization 
sensor to monitor the burner flame.
    CPSC also procured two contracts with ANSYS, Inc. (formerly DfR 
Solutions, Inc.) to estimate the expected lifespans of CO/combustion 
sensors while operating in a gas furnace or boiler application. The 
report titled ``Performance and Accelerated Life Testing of Carbon 
Monoxide and Combustion Sensors,'' dated May 28, 2019, is included as 
attachment 1 of Tab C of the Staff NPR Briefing Package. The report 
titled ``Performance and Accelerated Life Testing of Redesigned Carbon 
Monoxide and Combustion Gas Sensors,'' dated February 25, 2022, is 
included as attachment 2 of Tab C of the Staff NPR Briefing Package. 
The ANSYS report demonstrated that CO/combustion sensors are currently 
commercially available for use in gas appliances; the CO/combustion 
sensors that were tested had expected lifespans ranging from 6.4 to 10 
years operating under conditions that replicate the main stress 
conditions expected within a gas appliance.

B. Justification for Proposed Performance Requirements

    The proposed performance requirements are reasonably necessary and 
feasible for the following reasons:
     The gas furnaces and boilers under consideration are 
associated with an estimated 21 deaths per year, on average (2017-
2019), and an estimated total of 539 CO deaths from 2000 to 2019;
     the existing voluntary standards do not include provisions 
that would protect consumers from a number of conditions described in 
section IV of the preamble that are known to cause or contribute to the 
production, leakage into, and accumulation of dangerous concentrations 
of CO in the living space of a dwelling;
     there is no indication that the Z21/83 Technical Committee 
or any of the technical Subcommittees for gas furnaces and boilers 
intend to address this hazard; and
     continuous monitoring of the combustion process or the 
concentration of carbon monoxide within the combustion gases can be 
accomplished using commercially available CO/combustion sensing or 
combustion control technology.
    The proposed performance requirements described in this section of 
the preamble are intended to reduce the occurrence of CO-related 
deaths, injuries, and exposures associated with gas furnaces and 
boilers. Specifically, gas furnaces and boilers would continuously 
monitor CO emissions and shut down or modulate combustion if any of the 
average CO ranges specified in Table 1 \7\ are detected in the gas 
furnaces and boilers flue gases for the durations listed.
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    \7\ The proposed CO range setpoints and durations reflected in 
Table 1 are derived from UL 2034, Standard for Safety Single and 
Multiple Station Carbon Monoxide Alarms, 4th Edition, (2017), the 
voluntary standard for in-home carbon monoxide alarms. UL 2034 
provides requirements for electrically operated single and multi-
station CO alarms intended for protection in ordinary indoor 
locations of dwelling units. Section 41.1 of UL 2034 provides the 
levels at which a carbon monoxide alarm must trigger. Section 1.2 of 
UL 2034 covers carbon monoxide alarms intended to respond to the 
presence of carbon monoxide from various sources, including the 
abnormal operation of fuel-fired appliances.

      Table 1--CO Ranges and Durations for Shut-Down or Modulation
------------------------------------------------------------------------
                                                               Duration
                      Average CO (ppm)                         (minutes)
------------------------------------------------------------------------
500 or above................................................          15
400-499.....................................................          30
300-399.....................................................          40
200-299.....................................................          50
150-199.....................................................          60
------------------------------------------------------------------------

    The average CO ranges in Table 1 are the proposed setpoints and 
durations at which a gas furnace or boiler must either shut down or 
begin modulation. These CO ranges are based on Curve G of the CO 
Concentration vs. Time graph

[[Page 73279]]

(Figure 41.1 from UL 2034) in Figure 8 which indicates what an 
individual's carboxyhemoglobin (COHb) levels would be if exposed to 
various CO concentrations and the time of exposure needed to reach that 
COHb level. Curve G represents a 20 percent COHb level and the onset of 
health effects in individuals (i.e., a headache). The values on the y-
axis represent CO exposure levels in parts per million (ppm) from zero 
ppm CO to 1,800 ppm CO. The values on the x-axis represents the time 
durations (in minutes) of exposure to the CO concentrations presented 
on the y-axis. The curves A through J on the graph represent the 
various carboxyhemoglobin levels an individual can reach when exposed 
to CO (y-axis) over a period of time (x-axis).
[GRAPHIC] [TIFF OMITTED] TP25OC23.007

    To interpret the graph in Figure 8, begin at a given CO 
concentration on the y-axis and extend a horizontal line to the right 
until the line intersects a COHb curve. At the point of intersection, 
extend a vertical line downwards to the x-axis. The time value at this 
point of intersection represents the amount of time, at the selected CO 
concentration, at which an individual would reach a certain COHb level. 
For example, at a 400 ppm CO concentration, it would take approximately 
35 minutes for an individual to reach a COHb of 20 percent. At a CO 
concentration of 300 ppm, it would take approximately 50 minutes to 
reach a COHb of 20 percent. The dots on the graph in Figure 8 
illustrate that the entire proposed CO response range (i.e., 150-400 
and above) all fall on Curve G. A performance requirement that requires 
shutdown or modulation of a gas furnace or boiler at this range of CO 
levels provides protection to consumers from the onset of the more 
serious CO-related health effects, such as vomiting, coma, and death. 
The proposed performance requirement for the range and time period for 
CO exposure is consistent with the existing UL 2034 standard for 
consumer carbon monoxide alarms, which uses similar requirements to 
protect consumers from CO exposure in the home.
    Manufacturers may comply with the performance requirements under 
the proposed rule by using an option for either shut down or modulation 
of the gas furnace or boiler if the average CO level reaches 150 ppm 
over a 15-minute duration. This option simplifies the performance 
requirement to a single CO setpoint rather than multiple setpoints as 
described above. It provides the same level of protection as the 
multiple setpoint approach described above because the gas furnace or 
boiler would be required to shut down or modulate at the lowest 
threshold of CO production (150 ppm) that can result in low-level 
health effects (i.e., headache per the 20 percent COHb curve). The 
shorter time duration (15 minutes) is protective at higher CO 
concentrations of 200 ppm or more that can begin to cause the onset of 
health effects (i.e., a headache per the 20 percent COHb curve).
    The proposed performance requirements described in section VIII of 
the preamble are also based, in part on, on the definitions and 
performance requirements in ANSI Z21.47, Standard for Gas-fired central 
furnaces; ANSI Z21.13, Standard for Gas-fired low pressure steam and 
hot water boilers, and ANSI Z21.86, Standard for Vented gas-fired space 
heating appliances, as

[[Page 73280]]

well as performance requirements from CEN 8 9 standards for 
domestic gas boilers, and CEN standards for safety and control devices 
for gas appliances 10 11 and gas/air ratio controls for gas 
appliances,\12\ and JIS standard for domestic gas water heaters, 
boilers and space heaters.13 14 15 The CEN and JIS standards 
were given weight when developing the proposed performance requirements 
because the provisions in these standards are similar to the proposed 
performance requirements for gas furnaces and boilers in this NPR and 
are readily applicable to U.S. gas furnaces and boilers. In addition, 
although there are significant differences between the design platforms 
of European and Japanese gas boilers (i.e., predominantly premix power 
burner designs) and U.S. gas furnaces and boilers (i.e., predominantly 
induced draft and some atmospheric vent designs), the basic operating 
environment parameters (e.g., temperature, humidity, and combustion 
gases) within the heat exchangers and flues of European and Japanese 
gas boilers and U.S. gas furnaces and boilers are similar. The European 
and Japanese circumstances demonstrate the commercial availability of 
CO/combustion sensors and combustion controls that: (1) provide CO/
combustion sensor-based shutoff or reduced CO through combustion 
control; (2) are durable enough to survive in heat exchangers or flues 
of gas appliances; and (3) can be applied for use in U.S. gas furnaces 
and boilers.
---------------------------------------------------------------------------

    \8\ EN 15502-2-1, Gas-fired central heating boilers, Part 2-1: 
Specific standard for type C appliances and Type B2, B3 and B5 
appliances of a nominal heat input not exceeding 1,000 kW.
    \9\ EN 15502-2-2, Gas-fired central heating boilers Part 2-2: 
Specific standard for type B 1 appliances.
    \10\ BS EN 13611, Safety and control devices for burners and 
appliances burning gaseous and/or liquid fuels--General 
requirements.
    \11\ BS EN 16340, Safety and control devices for burners and 
appliances burning gaseous or liquid fuels--Combustion product 
sensing devices.
    \12\ Gas/air ratio controls for gas burners and gas burning 
appliances--Part 2: Electronic types
    \13\ JIS-S-2109, Gas burning water heaters for domestic use.
    \14\ JIS-S-2112. Gas hydronic heating appliances for domestic 
use.
    \15\ JIS-S-2122, Gas burning space heaters for domestic use.
---------------------------------------------------------------------------

    The proposed rule provides test methods to introduce a simulated 
400 ppm, 300 ppm, 200 ppm, and 150 ppm CO emission level into the 
exhaust gas to determine if the safety system passes or fails the 
proposed performance requirements.
    As explained in Tab B of the Staff NPR Briefing Package, staff 
assesses that the proposed rule would be 90 to 100 percent effective in 
preventing CO deaths and injuries associated with gas furnaces and 
boilers, because CO production at the gas furnace and boiler would be 
limited to levels that produce a headache in exposed consumers. Staff's 
assessment is based on the following key metrics used to assess the 
capability of the performance requirement in protecting consumers from 
the identified CO exposure risks:
     Detecting CO at the source of production: This provides a 
greater level of protection to consumers than residential CO alarms 
because it detects CO at the source of production within the gas 
furnace or boiler, before it leaks into a dwelling space, and allows 
for an earlier response time to protect consumers.
     Prevents or limits production of harmful levels of CO: 
Shutoff or modulation of the gas furnace or boiler directly addresses 
harmful CO production.
     Selecting CO response concentrations that fall on the 20 
Percent COHb curve: Selecting multiple CO response concentrations or a 
single, threshold CO concentration (150 ppm or higher) limits the 
severity of any potential health effects to a headache (i.e., the 20 
percent COHb curve).
     Addresses all known hazard patterns: Although the 
performance requirements do not prevent combustion product (including 
CO) leakage, the requirements do protect against serious harm from 
leakage of combustion products by limiting/preventing CO production.

VII. Response to Comments

    In response to the Commission's 2019 ANPR regarding residential gas 
furnaces and boilers, CPSC received 15 comments from the public, 
divided between supporters and opponents of the proposal. Opposing 
comments came primarily from the gas appliance industry. The comments 
can be found under docket number CPSC-2019-0020, at: 
www.regulations.gov. Below is summary of the comments and CPSC's 
responses by topic area.

Alternatives to Performance Requirements

    Comment: Nine commenters (A.O Smith, Carrier, Crown, Rheem, US 
Boiler Co. Edward Johan (USBC EJ), US Boiler Co. John Busse (USBC JB), 
Air Conditioning, Heating, and Refrigeration Institute (AHRI), Strauch, 
and Stanonik) asserted that rulemaking is not necessary because 
residential CO alarms will prevent CO poisoning from gas appliances. 
One commenter (Stanonik) further claimed that information from CPSC's 
IDI reports show that CO alarms are effective in protecting 
participants from exposure to hazardous levels of CO and that a survey 
being conducted by CPSC should be completed before rulemaking occurs. 
Four commenters (Crown, USBC EJ, USBC JB, and AHRI) supported changing 
the ANSI gas appliance standards and/or building codes to require CO 
alarm installation.
    Response: CPSC lacks statutory authority to mandate that consumers 
install CO alarms in their homes. Although the Commission urges use of 
residential CO alarms, not all homes are equipped with functioning and 
maintained CO alarms, and fewer still have them in all occupied spaces 
into which CO may leak from a gas furnace or boiler. Despite CPSC, 
state and local governments, and the private section information and 
education campaigns to increase the use of CO alarms, injuries and 
fatalities that occur annually are evidence that this hazard continues 
to kill and injure consumers, supporting the view that effective 
performance requirements for gas appliances are critical to consumer 
safety.
    Comment: USBC JB stated that a CO monitor in the equipment room or 
living space would provide a better solution than a CO monitor on the 
appliance.
    Response: A monitoring system located within the equipment room or 
living space would not necessarily detect CO at all foreseeable points 
of potential leakage along the length of the vent system. In contrast, 
detecting excessive CO leakage at the point of production on the 
appliance would protect consumers from CO exposure, regardless of the 
point or mechanism of leakage, or the cause of elevated CO production.
    Comment: USBC JB stated that CPSC should sponsor and provide 
funding for a multi-functional task force to develop solutions to 
reduce and eliminate CO poisoning caused by residential gas furnaces 
and boilers.
    Response: CPSC has contributed extensively to the development of 
proposed solutions to the CO hazard from gas furnaces and boilers. 
Staff's memorandum in Tab D of the Staff ANPR Briefing Package 
summarizes CPSC staff's efforts from 2000 to 2019 to work with the ANSI 
Z21/T83 Technical Committee to address carbon monoxide poisoning that 
was continuing to occur despite revisions to the gas appliance 
standards. CPSC staff conducted research and shared the results of that 
research, along with incident reports, with the Committee. Staff also 
submitted two proposals to the Technical Committee (in 2000 and 2015) 
requesting that the relevant voluntary standards add requirements to

[[Page 73281]]

address the production of hazardous levels of CO and the risk of that 
CO entering the living space of a dwelling. Despite staff's efforts 
over two decades, as well as the developments of voluntary standard 
requirements in Japan and Europe, the U.S. voluntary standards 
community has not adequately addressed the CO risk at the source of 
production in gas appliances. Indeed, in 2019 the Technical Committee 
disbanded the working group assessing possible revisions to the 
standards.
    Comment: USBC JB predicted that gas furnaces and boilers will 
eventually be replaced with electric heating appliances because current 
and future efforts to reduce carbon emissions will eliminate or 
restrict the availability of natural gas for residential appliances.
    Response: Gas appliances and boilers continue to be sold in large 
numbers for residential heating in the United States, without an 
effective voluntary solution to the CO hazard. Therefore, the 
Commission preliminarily concludes that mandatory performance 
requirements to address CO production by gas furnaces and boilers are 
necessary to reduce deaths and injuries from CO exposure that otherwise 
will continue to occur.
    Comment: USBC JB referred to periodic inspection and service of gas 
appliances and asked if CPSC's data addresses whether ``formalized 
inspection and service requirements would reduce carbon monoxide 
poisoning.'' Two other commenters (Crown and AHRI) asserted that a 
formal program to check installation, service, and maintenance will 
reduce carbon monoxide incidents.
    Response: CPSC lacks statutory authority to mandate homeowners' 
spending for maintenance services. Further, CPSC staff is not aware of 
data indicating that maintenance alone can address the deadly CO hazard 
from gas furnaces and boilers. Manufacturers already recommend routine 
maintenance of furnaces and boilers, yet injuries and deaths continue 
to occur for the reasons described above.
    Comment: Crown and USBC JB asserted that CPSC should rely on 
recalls to prevent/reduce CO incidents involving gas boilers and 
furnaces.
    Response: When a product is subject to a CPSC recall, the product 
already may have been involved in an incident, in this case a CO 
exposure incident that may have caused serious injury or death. The 
CPSC will continue to utilize the CPSA section 15 recall process, 
independent of this this rulemaking, but it is not a substitute for the 
proposed rule, which addresses elevated CO levels that may be unrelated 
to a defect in the furnace or boiler itself.

Rely on Consumer or Installer Education

    Comment: Carrier, Crown, Rheem, USBC EJ, and USBC JB stated that 
information and education programs for consumers, installers, and 
maintenance personnel will adequately address CO poisoning hazards.
    Response: Information and education campaigns currently exist, and 
yet numerous deaths and injuries continue to occur due to CO poisoning 
from gas furnaces and boilers demonstrating that these campaigns do not 
adequately address the hazard.
    Warnings rely on educating consumers about the hazard and 
persuading consumers to alter their behavior in some way to avoid the 
hazard. To be effective, warnings also depend on consumers noticing or 
otherwise receiving the message, attending to the message, remembering 
the recommended behaviors when needed, and behaving consistently, 
regardless of situational or contextual factors that influence 
precautionary behavior, such as fatigue, stress, or social influences. 
Thus, providing warnings and instructions about hazards is less 
effective than either designing the hazard out of a product or guarding 
the consumer from the hazard.

Rely on Voluntary Standards

    Comment: Commenters A.O. Smith, Rheem and the National Propane Gas 
Association (NPGA) stated that the CPSC should work with voluntary 
standards organizations to address the hazard.
    Response: Tab D of the Staff ANPR Briefing Package summarizes CPSC 
staff's efforts from 2000 to 2019 to work with the ANSI Z21/T83 
Technical Committee to address carbon monoxide poisoning incidents. As 
described above, despite staff's efforts, the voluntary standards 
organizations have not adopted adequate performance requirements to 
address the hazard.
    Comment: Carrier and AHRI noted that current appliance designs 
certified to the applicable ANSI/CSA Z21 safety standards already 
incorporate several safety features that reduce the risk of carbon 
monoxide production. These include blocked vent/intake switches, draft 
hood spill switches, and flame roll-out switches. Another commenter 
(USBC JB) stated that the ANSI standard for direct and non-direct vent 
boilers includes a test method to limit CO levels when the flue outlet 
is blocked or partially blocked, which USBC JB believes addresses the 
impact of snow blocking the vent. Stanonik stated that two-pipe or 
direct vent systems have fewer CO risks and some atmospherically vented 
appliances are not susceptible to depressurizing and back drafting that 
lead to CO exposure in the living space, and that these features, 
combined with the proper installation, service, and maintenance of the 
appliances, would eliminate the CO risk.
    Response: Blocked vent/intake pressure switches, draft hood spill 
switches, and flame rollout switches are all requirements that were 
added to and became effective in the standards between 1987 and 1993. 
Yet injuries and deaths from CO poisoning have continued to occur 
despite the existence of these voluntary standards provisions. Indeed, 
as discussed in Tab B of the Staff NPR Briefing Package, the particular 
voluntary standards provisions cited by these commenters have failed to 
prevent deaths and injuries in real-world scenarios.

Adverse/Unintended Consequences of Shut-Off Triggered by CO Sensor

    Comment: Six commenters (Carrier, Crown, USBC EJ, USG JB, AHRI, and 
Strauch) stated that improper shut-down of a gas appliance by a CO 
sensor will cause a no-heat hazard for consumers.
    Response: In response to these comments and other staff analyses, 
the proposed rule would require a fail-safe provision that would 
operate for the life of the appliance. If a CO sensor, combustion 
sensor, combustion control system, or other device designed to meet 
these requirements, fails to operate properly or at all, then the 
appliance shall shutdown and restart after 15 minutes, repeating this 
cycle and continuing to provide heat until the failed component is 
replaced, while also alerting the consumer of the hazard. For the life 
of the gas furnace or boiler, the proposed fail-safe provision would be 
required to notify consumers and service technicians of device failure 
by either a flashing light, or other appropriate code on the appliance 
control board, that corresponds to the device failure.
    Comment: Crown stated that a shut-down central heating appliance 
may encourage the use of less safe heating alternatives.
    Response: Shut-off devices on gas furnaces and boilers (e.g., BVSS, 
flame rollout switches, and over temperature limit switches) have been 
required by the ANSI Z21 standards for 25 to 30 years. However, we are 
not aware of any trends of consumers using less safe heating 
alternatives as the result of these other safety shut-down devices on 
these

[[Page 73282]]

products. Furthermore, the proposed rule has a fail-safe provision, as 
described above, which provides warning to consumers of a CO sensor 
issue without complete loss of functionality of the gas furnace or 
boiler.

Carbon Monoxide Sensor--Sensitivity and Durability

    Comment: American Gas Association (AGA) and USBC JB asserted that 
measuring ``air-free'' CO concentrations benchmarked to the ANSI-
recognized ``safe'' concentration of 400 ppm would be complex because a 
carbon monoxide monitor measures ``raw'' CO concentrations which 
includes the ``air-free'' carbon monoxide concentration multiplied by 
the ratio of air that was not used in combustion. Consequently, the 
air-free CO will always be lower than the measured CO.
    Response: CPSC staff agrees that an air-free measurement 
calculation would be more complex since it would require the 
measurement of carbon dioxide or oxygen as well, and the proposed rule 
does not require this calculation.
    Comment: USBC JB stated that the performance of existing CO sensors 
has not been established at the 400 ppm level and lower.
    Response: In general, sensor manufacturers specify the maximum and 
minimum concentration range that a sensor can detect, as well as 
whether the sensor provides a linear output voltage in response to the 
gas (i.e., CO) it's designed to detect. For example, if a manufacturer 
specifies that their sensor has a linear response range of 0 to 10,000 
ppm of CO, then the sensor can detect between 0 and 10,000 ppm CO, 
including 400 ppm CO or lower. CPSC staff has identified multiple CO 
sensors with an advertised linear response range that extends below 400 
ppm.
    Comment: Strauch asserted that research does not show that CO 
sensors are durable enough to last for 15 to 20 years. Another (USBC 
JB) stated that performance requirements normally address device 
tolerances to allow conformance at prescribed conditions and avoid 
nuisance issues.
    Response: We do not agree with the premise that CO sensors must 
have a 15-to-20 year lifespan in order for the proposed rule to be 
effective. Many parts may fail during the lifetime of a gas furnace or 
boiler, resulting in the need for replacement or a service call to fix 
or replace the part. CO sensors would be expected to be treated in this 
same manner as other parts that need to be replaced during the lifespan 
of the product. The costs of such services are included in the 
preliminary regulatory analysis in section IX of the preamble. 
Regarding the comment about tolerances, manufacturers will need to 
select appropriate sensors and other equipment to ensure that their 
furnaces and boilers comply with the proposed standard.

Requirements in International Standards

    Comment: Crown and USBC JB asserted that there is no widespread use 
of CO sensors in gas appliances in Europe and Japan. One commenter 
(AHRI) observed that ``the EN standards (EN 15502-1, EN 15502-2-1 and 
EN 15502-2-2) do not require manufacturers to incorporate a CO-sensor 
shut-off device within the appliance.'' In addition, that commenter 
stated none of the U.S. or international standards, including JIS S 
2019, specifically require a CO sensor within the appliance. AHRI 
stated that the most commonly used CO sensor, manufactured by Nemoto 
Sensor Engineering, Ltd., is designed to work when carbon monoxide 
levels exceed 1000 ppm.
    Response: While the Japanese standard, JIS S 2019, and the European 
standards, EN 15502-2-1 and EN 15502-2-2, do not specifically require a 
CO sensor in-situ (i.e., within the heater exchanger or flue passage 
ways of the appliance), each standard includes an option that allows 
for CO and combustion sensors in-situ if the manufacturer chooses to 
use that approach to meet the requirements of the respective standards. 
Some European and Japanese gas boilers products certified to those 
standards are equipped with CO sensor shutoff capability. More 
generally, the existence of the option to use CO sensors incorporated 
in-situ to meet the requirements of respective standards reinforces 
that such sensors are feasible. Regarding Nemoto sensors, the published 
Nemoto product literature (https://sensor.nemoto.co.jp/en/product/detail/nap-78su/) indicates that the CO sensors in question have a 
linear response range of zero to 10,000 ppm CO; thus the sensors in 
question are represented by Nemoto to have the capability to provide an 
output voltage response to all of the CO levels within that range, 
including 400 ppm CO and lower.

Feasibility of Performance Requirements With Existing CO/Combustion 
Technology

    Comment: Carrier and AHRI stated that ``a minimum of 20 years is 
needed to replace existing residential gas appliances with a carbon 
monoxide sensor-equipped appliances'' based on the anticipated lifespan 
of an appliance. USBC JB stated that it would take a minimum of two to 
three years to develop and validate performance requirements and then 
revise the voluntary standards through the consensus process.
    Response: We agree that it will take time for existing gas furnaces 
and boilers to be replaced by newly installed equipment that meets the 
requirements of the proposed rule mandating additional safety features 
for future gas furnaces and boilers; inasmuch as the proposed rule does 
not require replacement of existing installed gas furnaces and boilers 
and would only apply to the future manufacture of gas furnaces and 
boilers. This is reflected in the preliminary regulatory analysis in 
Section IX of the preamble. Approximately two million gas furnaces and 
800,000 gas boilers without CO sensors are sold each year, thus 
prolonging the time it would take to replace old stock. As a result, 
each year of further delay in instituting safety features to address 
the CO hazard will result in millions of units without these features 
being sold and installed and remaining in homes for multiple decades, 
risking additional preventable deaths and injuries.
    Comment: Carrier and AHRI stated that CO sensors will not detect 
leakage from the venting system.
    Response: The proposed rule focuses on the source rather than 
leakage points throughout the exhaust path because of the extent, 
variability, and potential inaccessibility of the exhaust path in 
homes. We agree that a CO sensor will not detect leakage from a venting 
system. However, CO detection at the source of production would provide 
protection to consumers regardless of the location of downstream 
leakage. For these reasons, we disagree with AHRI's assertion that a CO 
sensor-equipped appliance would be ineffective against a compromised 
vent.
    Comment: A.O. Smith stated that CO sensors in a gas appliance 
cannot easily be replaced in the field.
    Response: The commenter provided no technical evidence to support 
the claim that CO sensors cannot be installed so that they are easily 
replaced in the field. CPSC staff is aware of and has access to gas 
appliances that utilize CO sensors, air/fuel ratio sensors, and other 
combustion control devices within the combustion chamber of flue 
passageways to provide CO safety and/or energy efficiency. CO sensors 
are no more complex and do not present any greater difficulty in 
gaining access to the

[[Page 73283]]

devices for maintenance or replacement than other safety devices, such 
as pressure switches, flame sensors, and flame rollout switches, 
currently required by the ANSI standards for gas appliances. Sensors 
are comprised of a sensing element covered by shielding and a mounting 
flange. Typically, the shielded, sensing element is inserted through an 
access hole through the bulkhead of a combustion chamber, plenum, or 
flue passageway. The sensor is generally mounted to the bulkhead with 
two screws with a heat-resistant gasket between the mounting flange and 
the bulkhead. We assess that CO sensors in a gas appliance could be 
replaced in consumer homes in a manner similar to other existing gas 
furnace or boiler components that are currently serviced and replaced 
in consumer homes.
    Comment: Rheem asserted that some of the referenced/observed 
failure modes in the ANPR cannot be addressed through appliance design 
alone.
    Response: We do not agree with the assertion that failure mode 
issues cannot be addressed through appliance design. By ensuring that 
harmful levels of CO are not produced in the gas furnace or boiler, the 
proposed requirements remove the need to provide protection throughout 
the entire exhaust vent system.
    Comment: Stanonik stated that the document ``Findings from CPSC's 
2014 Carbon Monoxide/Combustion Sensor Forum and Request for 
Information'' (https://www.cpsc.gov/s3fs-public/pdfs/blk_pdf_Findings-from-the-FY14-Sensor-Forum-and-RFI.pdf) indicates that a specific 
sensor technology that appeared to address durability and longevity 
concerns is very expensive and reflected the ``significant process'' 
involved in developing durable and reliable sensor products.
    Response: We agree that the cost the commenter referenced would be 
high. However, the sensing technology in question was an evaluation 
unit, not a full-scale production unit, and came with electronic 
controls necessary to operate and evaluate the sensor, resulting in 
elevated costs for that particular sensing technology. The cost per 
unit typically goes down with large-scale production. CPSC staff 
estimates costs for volume purchases in the range of approximately $5 
to $15 per unit. The preliminary regulatory analysis in section IX of 
the preamble provides further analysis of potential costs and benefits.

VIII. Description of the Proposed Rule

    The proposed rule would create a new part 1408, ``Safety Standard 
for Residential Gas Furnaces and Boilers.'' The provisions of the 
proposed rule are described below.

A. Proposed Section 1408.1 Scope, Purpose, and Effective Date

    Proposed section 1408.1 provides that new part 1408 establishes a 
consumer product safety standard that would provide performance 
requirements for residential gas furnaces and boilers that are consumer 
products used to heat dwellings. The purpose of these requirements is 
to reduce the occurrence of carbon monoxide-related deaths, injuries, 
and exposures associated with gas furnaces, boilers, and wall and floor 
furnaces. All requirements of the proposed rule apply to all 
residential gas furnaces, boilers, and wall and floor furnaces that are 
manufactured after the proposed effective date, which is 18 months 
after publication of the final rule in the Federal Register.

B. Proposed Section 1408.2 Definitions

    Proposed section 1408.2 provides definitions that apply for 
purposes of part 1408. Proposed section1408.2 provides definitions for 
the covered categories of furnaces and boilers. The proposed 
definitions are based on the definitions used in ANSI Z21.47-2021, ANSI 
Z21.13-2022, and ANSI Z21.86-2016 for the same product types.

C. Proposed Section 1408.3 Performance Requirements for Gas Furnaces 
and Boilers

    Proposed section 1408.3 provides general requirements, performance 
requirements, test configuration, and test methods for all residential 
gas furnaces and boilers. Section VII.B of the preamble provides the 
technical justification for these proposed requirements.
1. Proposed Section 1408.3(a) (General Requirements)
    Proposed section 1408.3(a) provides that all residential gas 
furnaces and boilers must have a means to either directly or indirectly 
monitor the concentration of carbon monoxide produced during the 
combustion process and shut down or modulate combustion to reduce 
average CO concentrations to below the CO levels for the durations of 
time specified in proposed section 1408.3(b). The gas furnace or boiler 
must either shut down or modulate combustion to reduce average CO 
emissions to below 150 ppm if the average CO emissions reach or exceed 
the CO limits and time durations specified in section 1408.3(b).
    Proposed section 1408.3(a) also states that indirect monitoring and 
control of CO emissions can be accomplished by monitoring and 
controlling other combustion parameter(s) that accurately correlate to 
the production of CO. Proposed section 1408.3(a) provides examples of 
parameters that can serve as a proxy for CO production such as carbon 
dioxide (CO2), oxygen (O2), the Gas/Air Ratio, 
and the flame ionization current produced by the burner flame.
2. Proposed Section 1408.3(b) (Performance Requirements)
    Proposed section 1408.3(b) provides a performance requirement that 
a gas furnace or boiler must be equipped with a means to continuously 
monitor CO emission and must meet the requirements described in either 
proposed section 1408.3(b)(1) or (b)(2) (direct means to monitor CO 
emissions) or (b)(3) or (4) (indirect means to monitor CO emissions) 
when tested using the test method described in proposed section 
1408.3(d). Proposed paragraphs 1408.3(b)(1) and (2) provides two 
options for gas furnaces and boilers manufacturers to use direct means 
to monitor CO emissions that must cause either shut-down or modulation 
of the gas furnace or boiler combustion, based on conditions within the 
gas furnace or boiler for a range of specified average CO 
concentrations for the specified time frames. Proposed section 
1408.3(b)(3) provides two options for gas furnace and boiler 
manufacturers to use an indirect means to monitor CO emissions that 
must either cause shut-down of the gas furnace or boiler or cause 
modulation of combustion of the gas furnace or boiler, based on 
conditions within the gas furnace or boiler for a range of specified 
average CO concentrations for the specified time frames described.
    Proposed section 1408.3(b)(4) provides a fail-safe requirement that 
during the life of the gas furnace or boiler, if a CO sensor, 
combustion sensor, combustion control system, or other device designed 
to meet these requirements fails to operate properly or at all, then 
the gas furnace or boiler must shutdown and restart after 15 minutes 
and repeat this cycle until the failed component is replaced. The 
requirement mandates that consumers and service technicians must be 
notified of device failure by either a flashing light, or other 
appropriate code on the gas furnace or boiler control board, that 
corresponds to the device failure.
3. Proposed Section 1408.3(c) (Test Configuration)
    Proposed section 1408.3(c) describes the requirements that gas 
furnace or boilers must be configured in

[[Page 73284]]

accordance with the provisions of the combustion sections of the 
respective voluntary standards (section 5.8.1 of ANSI Z21.47-2021 for 
gas furnaces; section 5.5.1 of ANSI Z21.13-2022 for gas boilers; and 
sections 9.3.1, 11.2.1, and 13.3.1, of ANSI Z21.86-2016 for gas wall 
and floor furnaces) with respective instruction on how products are to 
be configured before testing to proposed section 1408.3(d).
4. Proposed Section 1408.3(d) (Test Procedure)
    Proposed section 1408.3(d) provides the test procedure to be used 
to test a gas furnace or boiler after the product has been configured 
pursuant to proposed section 1408.3(b) to demonstrate compliance with 
the performance requirements provided in proposed section 1408.3(b).

D. Proposed Section 1408.4 Incorporation by Reference

    Proposed section 1408.4 incorporates by reference ANSI Z21.47-2021, 
ANSI Z21.13-2022, and ANSI Z21.86-2016 regarding the test setup cited 
in proposed section 1408.3 and provides information on where the 
standards are available.

E. Proposed Section 1408.5 Prohibited Stockpiling

    Pursuant to section 9(g)(2) of the CPSA, 15 U.S.C. 2058(g)(2), the 
proposed rule would prohibit a manufacturer from ``stockpiling'' or 
substantially increasing the manufacture or importation of noncompliant 
gas furnaces and boilers between the date publication of the final rule 
and the effective date. The provision, which is explained more fully in 
Tab D of the Staff NPR Briefing Package, would prohibit the manufacture 
or importation of noncompliant products at a rate that is greater than 
106 percent of the base period in the first 12 months after 
promulgation, and 112.50 percent of the base period for the duration of 
12 months after promulgation until the effective date. The base period 
is defined in the proposed rule as the calendar month with the median 
manufacturing volume, among months with manufacturing volume, during 
the last 13 months prior to the rule's publication.
    We propose a rate of 106 percent for the first 12 months and a rate 
112.50 percent in the final 6 months between publication and effective 
date based on the historical growth of the industry. We propose a 
higher rate of 112.50 percent for the second year to account for the 
baseline growth of the industry in the second year.
    Individual manufacturers may experience growth rates outside the 
historical range. Shipment data for gas furnaces and boilers show a 
steady, yet seasonal, market. Shipments of gas furnaces and boilers 
begin to rise in March and continuously increase until December, after 
which they fall off sharply. The Commission seeks public comment on 
manufacturing, the seasonality of sales, and supply chain of gas 
furnaces and boilers to further understand these topics.

F. Appendix A to Part 1408--Findings Under the Consumer Product Safety 
Act

    The findings required by section 9 of the CPSA are discussed 
throughout this preamble and set forth in Appendix A to the proposed 
rule.

IX. Preliminary Regulatory Analysis

    Pursuant to section 9(c) of the CPSA, publication of a proposed 
rule must include a preliminary regulatory analysis containing:
     A preliminary description of the potential benefits and 
potential costs of the proposed rule, including any benefits or costs 
that cannot be quantified in monetary terms, and an identification of 
those likely to receive the benefits and bear the costs;
     a discussion of why a relevant voluntary safety standard 
would not eliminate or adequately reduce the risk of injury addressed 
by the proposed rule; and
     a description of any reasonable alternatives to the 
proposed rule, together with a summary description of their potential 
costs and benefits and why such alternatives should not be published as 
a proposed rule.
    This preamble contains a summary of the preliminary regulatory 
analysis for the proposed rule. Tab D of the Staff NPR Briefing Package 
contains a detailed analysis.

A. Market Information

1. The Product
    Gas furnaces and boilers are vented gas heating appliances that 
heat residential dwellings. Section III of the preamble provides a 
detailed discussion of the nature and operation of gas furnaces and 
boilers. The average product life for gas furnaces and boilers ranges 
from approximately 22 to 25 years.
    Gas furnaces and boilers include central warm-air furnaces and 
boilers as well as floor, and wall furnaces.
     Central warm-air furnaces and boilers use a central 
combustor, or boiler, to heat air using natural gas, and liquid 
propane. Some of these furnaces move the heated air using a blower or 
fan through ducts while others rely on the natural flow of warm air 
going up and cold air down to circulate air. Most boilers supply steam 
or hot water through conventional radiators or baseboard radiators.
     Floor and wall furnaces are less common than central 
furnaces and boilers and consist of ductless combustors to heat air. A 
floor furnace and wall furnace heat the physical parts of the house 
(i.e., floor or wall) to heat the dwelling. A furnace is typically 
located in a basement and delivers heated air through a large register 
in the floor above it.
    Consumers purchase gas furnaces and boilers primarily through 
contract installers, but they may also purchase units at retail stores 
and online retailers. CPSC staff estimate the average retail price of 
gas furnaces to be $1,660 and $3,719 for gas boilers.
2. Market Trends for Gas Furnaces and Boilers
    Staff identified as many as 70 firms that manufacture or import 
residential gas furnaces and boilers. When accounting for subsidiaries 
and multiple brands provided by the same company, staff identified 20 
parent firms. In 2016, the largest 10 firms by revenue accounted for 
83.3 percent of heating equipment sales. Seven of these firms are based 
in the U.S.
    Department of Energy's (DOE) most recent Residential Energy 
Consumption Survey (RECS) reports the total number of gas furnaces, gas 
boilers, and wall furnaces in-use to be 60.94 million in 2020. This is 
an increase from 57.90 million in 2015. Between 2015 and 2020, 
therefore, the number of in-scope gas furnaces and boilers grew at an 
average annual rate of 1.03 percent.
    DOE's Government Regulatory Impact Model (GRIM) projects gas 
furnace sales in 2021 to be 3.58 million units and gas boilers to be 
0.30 million units. CPSC staff estimated that residential gas furnaces 
and boilers sales in 2021 to be $5.94 billion and $1.12 billion, 
respectively.
    CPSC staff estimate that residential gas boiler imports average 
$117.67 million annually. The Commission requests comment on the value 
and quantity of gas furnaces and boilers imports that would be subject 
to a proposed rule.
3. Future Market Size for Gas Furnaces and Boilers
    Staff used a 1.03 percent annual growth rate derived from DOE's 
GRIM to project sales into the future. Using this approach, staff 
estimates the number of

[[Page 73285]]

in-use, in-scope gas furnaces and boilers will grow from 64.13 million 
in 2025 to 90.49 million in 2054.

B. Preliminary Description of Potential Costs and Benefits of the Rule

    Staff conducted a cost assessment of the proposed rule. The 
proposed rule would impose the following costs: increased variable 
costs of producing furnaces and boilers with CO sensors and shutoff 
capabilities; one-time conversion costs of redesigning and modifying 
factory operations for installing CO sensors; increased maintenance 
costs of gas furnaces and boilers to consumers; and deadweight loss 
\16\ in the market caused by the increasing price due to regulation and 
the subsequent decline in sales. Staff performed a 30-year prospective 
cost assessment (2025-2054) on all four cost categories and estimated 
the total annualized cost from the proposed rule to be $602.27 million, 
discounted at three percent.\17\ Staff estimated the per-unit cost of a 
gas furnace or boiler from the proposed rule to be $158.11, discounted 
at three percent.
---------------------------------------------------------------------------

    \16\ Deadweight loss is the value of lost transactions that may 
occur after major market events such as a new regulation.
    \17\ Staff uses a discount rate to incorporate the time value of 
money during the 30-year study period. In the analysis, staff 
presents both costs and benefits in undiscounted dollars, discounted 
at three percent, and discounted at seven percent.
---------------------------------------------------------------------------

    Staff also conducted a benefits assessment of the proposed rule. 
The benefits assessment accounted for the prevention of deaths and 
injuries from compliant gas furnaces and boilers, which staff monetized 
using the Value of Statistical Life (VSL) for deaths, and the Injury 
Cost Model (ICM) for injuries. Over the 30-year study period, staff 
estimated the proposed rule would prevent 576 deaths (19.20 deaths per 
year) and 160,699 injuries (5,357 per year). The total annualized 
benefits from the proposed are $356.52 million, discounted at three 
percent. Staff estimated the per-unit benefits from the proposed rule 
to be $93.60, discounted at three percent. Staff calculates net 
benefits (benefits less costs) to be -$245.74 million on annualized 
basis, discounted at three percent. The net benefits on per-unit basis 
are -$64.51, discounted at three percent. Alternatively, this can be 
described as the proposed rule being a net cost of $64.51 per gas 
furnace or boiler, which represents approximately three percent of the 
average price of a gas furnace or boiler, to prevent an estimated 576 
deaths and 160,699 injuries over 30 years.
    Finally, staff conducted a sensitivity analysis that showed if, by 
2035 manufacturers were able to develop compliant gas furnaces and 
boilers with CO sensors that did not need replacement, and if the 
analysis took into account that a child's death is considered twice as 
costly as an adult death,\18\ the benefit-cost ratio would increase to 
0.78.
---------------------------------------------------------------------------

    \18\ For more information see CPSC's Draft Guidance for 
Estimating Value per Statistical Life (88 FR 17826), https://www.federalregister.gov/documents/2023/03/24/2023-06081/notice-of-availability-proposed-draft-guidance-for-estimating-value-per-statistical-life.
---------------------------------------------------------------------------

C. Evaluation of Voluntary Standards

    Based on staff's evaluation of the relevant ANSI standards 
discussed in section V of the preamble, the Commission preliminarily 
determines that current U.S. voluntary standards do not adequately 
address the hazard of CO exposure from gas furnaces and boilers. 
Further, the Z21/83 Technical Committee and the subordinate Technical 
Subcommittees have no clear plan to address these hazards in the 
relevant voluntary standards. None of the commenters on the ANPR 
submitted any recommendations for proposed requirements, nor did any 
commenters submit an existing voluntary standard or a portion of one 
that would adequately address the CO exposure risk that this proposed 
rule would address. No standard or portion of a standard was submitted 
to the Commission under section 9(a)(5) of the CPSA.

D. Alternatives to the Proposed Rule

    The Commission considered four alternatives to the proposed rule: 
(1) continue to work and advocate for change through the voluntary 
standards process; (2) rely on the use of residential CO alarms; (3) 
continue to conduct education and information campaigns; and (4) rely 
on recalls. Each alternative is discussed in detail below.
1. Continue To Work and Advocate for Change Through the Voluntary 
Standards Process
    Section V of this preamble highlights CPSC staff's participation in 
the voluntary standard development process for ANSI Z21.47, Z21.13, and 
Z21.86. Despite staff encouraging industry to adopt a standard that 
adequately addresses the hazard, and providing industry with the 
necessary factual foundation, industry has not adopted such a standard 
in over 20 years. For this reason, the Commission is not adopting this 
alternative.
2. Rely on the Use of Residential CO Alarms
    CPSC has long promoted CO alarm adoption and states have 
increasingly required CO alarms in homes over the last two decades. Yet 
there has not been a significant decline in CO injuries and fatalities, 
demonstrating that CO alarm adoption alone is insufficient to address 
the hazard. We also note that residential CO alarms may fail to alert 
due to battery failure, poor maintenance, manufacturer defect, age, 
incorrect installation, or defects. Finally, a CO alarm would not shut 
down a gas furnace or boiler producing a dangerous amount of CO and 
thus would require the occupant to properly recognize what to do when 
the alarm is triggered. For these reasons, the Commission is not 
adopting this alternative.
3. Continue To Conduct Education and Information Campaigns
    Despite education and information campaigns by CPSC and others 
regarding CO hazards, CO death and injuries for gas furnaces and 
boilers remain high. Education and information campaigns alone have not 
adequately addressed the CO hazard from gas furnaces and boilers in the 
absence of a performance standard. For these reasons, the Commission is 
not adopting this alternative.
4. Rely on Recalls
    Although not all instances of excessive CO concentrations result 
from a defect in the gas furnace or boiler, the Commission could seek 
voluntary or mandatory recalls of gas furnaces and boilers that present 
a substantial product hazard. Recalls only apply to an individual 
manufacturer and product, and generally do not extend to similar 
products, and occur only after consumers have purchased and used such 
products with possible resulting deaths or injuries due to exposure to 
the hazard. Additionally, recalls can only address products that are 
already on the market but do not directly prevent unsafe products from 
entering the market. In the absence of a rule, hazardous gas furnaces 
and boilers will continue to see sales of several million units 
annually and the stock of hazardous products will continue to grow. 
Additionally, while detached gas furnaces and boilers could be easily 
recalled, installed gas furnace and boiler recalls can be disruptive 
and costly. For these reasons, the Commission does not choose this 
alternative.

[[Page 73286]]

X. Initial Regulatory Flexibility Analysis

    Whenever an agency publishes an NPR, Section 603 of the Regulatory 
Flexibility Act (RFA), 5 U.S.C. 601-612, requires the agency to prepare 
an initial regulatory flexibility analysis (IRFA), unless the head of 
the agency certifies that the rule will not have a significant economic 
impact on a substantial number of small entities. The IRFA, or a 
summary of it, must be published in the Federal Register with the 
proposed rule. Under Section 603(b) of the RFA, each IRFA must address:
    (1) a description of why action by the agency is being considered;
    (2) a succinct statement of the objectives of, and legal basis for, 
the proposed rule;
    (3) a description of and, where feasible, an estimate of the number 
of small entities to which the proposed rule will apply;
    (4) a description of the projected reporting, recordkeeping, and 
other compliance requirements of the proposed rule, including an 
estimate of the classes of small entities which will be subject to the 
requirement and the type of professional skills necessary for 
preparation of the report or record; and
    (5) an identification, to the extent practicable, of all relevant 
Federal rules which may duplicate, overlap, or conflict with the 
proposed rule.
    The IRFA must also describe any significant alternatives to the 
proposed rule that would accomplish the stated objectives and that 
minimize any significant economic impact on small entities.

A. Reason for Agency Action

    The intent of this rulemaking is to reduce deaths and injuries 
resulting from carbon monoxide leaks from gas furnaces and boilers by 
establishing a mandatory performance standard requiring gas furnaces 
and boilers to shut off or modulate when CO levels reach specified 
amounts for a certain duration.

B. Objectives of and Legal Basis for the Rule

    The Commission proposes this rule to reduce the risk of death and 
injury associated with CO leakage from residential gas furnaces and 
boilers. This standard is promulgated under the authority of the CPSA. 
To issue a mandatory standard under CPSA section 7, 15 U.S.C. 2056, the 
Commission must follow the procedural and substantive requirements in 
section 9 of the CPSA, 15 U.S.C. 2058. See 15 U.S.C. 2056(a).

C. Small Entities to Which the Rule Will Apply

    The proposed rule would apply to all manufacturers and importers of 
gas furnaces and gas boilers. CPSC staff is aware of as many as 70 
firms manufacturing gas furnaces and boilers for the U.S. market. When 
accounting for subsidiaries and multiple brands provided by the same 
company, staff identified 20 parent firms.
    Using SBA guidelines, staff identified two small manufacturers of 
gas furnaces, three small manufactures of residential gas boilers, and 
one importer of gas furnaces that may fall within the scope the rule. 
The Commission requests comment on additional manufacturers and 
importers of gas furnaces and boilers that may meet the SBA definition 
of a small business.

D. Compliance, Reporting, and Record-Keeping Requirements of Proposed 
Rule

    In accordance with Section 14 of the CPSA, 15 U.S.C. 2063, 
manufacturers would have to issue a General Certificate of Conformity 
(GCC) for each of their gas furnace or boiler models, certifying that 
the model complies with the proposed performance requirement. Each GCC 
must also be based on a test of each product or a reasonable testing 
program and provided to all distributors or retailers of the product. 
The manufacturer would have to comply with 16 CFR part 1110 concerning 
the content of the GCC, retention of the associated records, and any 
other applicable requirements.

E. Federal Rules That May Duplicate, Overlap, or Conflict With the 
Proposed Rule

    No Federal rules duplicate, overlap, or conflict with the proposed 
rule.

F. Potential Impact on Small Entities

1. Impact on Small Manufacturers
    The preliminary regulatory analysis in Section IX of this preamble 
discusses costs more fully. Based on that analysis, to achieve 
compliance with the proposed rule's performance requirements, small 
domestic manufacturers would incur costs from the increased variable 
costs of producing furnaces and boilers with CO sensors and shutoff 
capabilities and testing and certifying such products, as well as the 
one-time conversion costs of redesigning and modifying factory 
operations for installing CO sensors.
    Installing CO sensors and shutoff capabilities in a gas furnace or 
boiler is a variable cost that is attached to each unit produced. Staff 
used a Guidehouse study (Guidehouse 2021) to find that the cost to 
manufacturers (without any markup included) at an annual production 
level of 119,572 gas furnace and boiler units yields an average 
incremental cost of $66.47 per unit.\19\ This is an annual total of 
$7.95 million ($66.47 x 119,572) for each small firm.
---------------------------------------------------------------------------

    \19\ Weighted average between retail price increase from gas 
furnaces ($65.22) and boilers ($81.10) for the first year impact of 
the rule.
---------------------------------------------------------------------------

    Regarding the one-time conversion costs, DOE's findings from its 
2015 Rules on Gas Residential Furnaces and Boilers (80 FR 13120 and 80 
FR 17222) found an industry cost of $413.28 million (inflated to 2021 
dollars).\20\ This would suggest a maximum conversion cost for small 
firms of $69.02 million (16.7 percent x $413.28 million) or $13.80 
million per firm among the small five manufacturers.
---------------------------------------------------------------------------

    \20\ Conversion costs were calculated in 2013 dollars and 
reported in 2020 dollars adjusted for 2013-2020 inflation using the 
Consumer Price Index-Urban.
---------------------------------------------------------------------------

2. Impact on Small Importers
    Staff identified one small importer of products that would be 
within the scope of the standard. Importers may pass on testing 
responsibility and GCC creation to the foreign manufacturers and then 
issue the resulting certificate. Changes in production and 
certification costs incurred by suppliers from the standard could be 
passed on to the importers, which in turn are likely to be passed onto 
consumers given the relatively inelastic demand for heating appliances. 
For this reason, the Commission does not believe that the proposed rule 
will have a significant impact on small importers.
    The Commission seeks public comment on information on importers of 
gas furnaces and boilers; specifically, how many are imported, how many 
different models each importer sells, and what technologies those 
models are currently using (atmospheric venting, condensing, non-
condensing, premix power burners, etc.). The Commission also seeks 
public comment on information regarding to what degree supplying firms 
tend to pass on increases in production and regulatory costs to 
importers, and to what extent the ability to pass on these costs is 
limited by the ease with which importers can switch suppliers or 
substitute to alternative products, such as electrical furnaces and 
boilers.

G. Alternatives for Reducing the Adverse Impact on Small Businesses

    The Commission considered four alternatives to the proposed rule: 
(1) continue to work and advocate for change through the voluntary 
standards

[[Page 73287]]

process; (2) rely on the use of residential CO alarms; (3) rely on 
education and information campaigns; and (4) rely on recalls. The 
Commission is not adopting these alternatives for the reasons in 
Section IX of the preamble.
    The Commission welcomes public comments on this IRFA. Small 
businesses that believe they would be affected by the proposed rule are 
encouraged to submit comments. The comments should be specific and 
describe the potential impact, magnitude, and alternatives that could 
reduce the impact of the proposed rule on small businesses.

XI. Incorporation by Reference

    The Commission proposes to incorporate by reference: ANSI Z21.47-
21, Standard: Gas-fired central furnaces; ANSI Z21.13-22, Standard: 
Gas-fired low-pressure steam and hot water boilers; and ANSI Z21.86-16, 
Standard: Vented Gas-fired space heating appliances. The Office of the 
Federal Register (OFR) has regulations regarding incorporation by 
reference. 1 CFR part 51. Under these regulations, agencies must 
discuss, in the preamble to a final rule, ways in which the material 
the agency incorporates by reference is reasonably available to 
interested parties, and how interested parties can obtain the material. 
In addition, the preamble to the final rule must summarize the 
material. 1 CFR 51.5(b)(3).
    In accordance with the OFR regulations, section IV of this preamble 
summarizes the major provisions of ANSI Z21.47-21, Standard: Gas-fired 
central furnaces; ANSI Z21.13-22, Standard: Gas-fired low-pressure 
steam and hot water boilers; and ANSI Z21.86-16, Standard: Vented gas-
fired space heating appliances that the Commission incorporates by 
reference into 16 CFR part 1408. The standard itself is reasonably 
available to interested parties. Until the final rule takes effect, 
read-only copies of ANSI Z21.47-21, Standard: Gas-fired central 
furnaces; ANSI Z21.13-22, Standard: Gas-fired low-pressure steam and 
hot water boilers, and ANSI Z21.86-16, Standard: Vented gas-fired space 
heating appliances are available for viewing, at no cost, at https://community.csagroup.org/login.jspa?referer=%252Fgroups%252Fansi-standards-view-access. Once the rule takes effect, a read-only copy of 
the standards will be available for viewing, at no cost, at https://community.csagroup.org/login.jspa?referer=%252Fgroups%252Fansi-standards-view-access. Interested parties can also schedule an 
appointment to inspect a copy of the standard at CPSC's Office of the 
Secretary, U.S. Consumer Product Safety Commission, 4330 East West 
Highway, Bethesda, MD 20814, telephone: (301) 504-7479; email: [email protected]. Interested parties can purchase a copy of the three ANSI 
standards from the Canadian Standards Association, 8501 East Pleasant 
Valley Road Independence, OH 44131-5516: 1-800-463-6727; 
www.csagroup.org/store/.

XII. Environmental Considerations

    Generally, the Commission's regulations are considered to have 
little or no potential for affecting the human environment, and 
environmental assessments and impact statements are not usually 
required. See 16 CFR 1021.5(a). The proposed rule is not expected to 
have an adverse impact on the environment and is considered to fall 
within the ``categorical exclusion'' for the purposes of the National 
Environmental Policy Act. 16 CFR 1021.5(c).

XIII. Preemption

    Executive Order (E.O.) 12988, Civil Justice Reform (Feb. 5, 1996), 
directs agencies to specify the preemptive effect of a rule in the 
regulation. 61 FR 4729 (Feb. 7, 1996). The proposed regulation for gas 
furnaces and boilers is being promulgated under authority of the CPSA. 
15 U.S.C. 2051-2089. Section 26 of the CPSA provides that:

whenever a consumer product safety standard under this Act is in 
effect and applies to a risk of injury associated with a consumer 
product, no State or political subdivision of a State shall have any 
authority either to establish or to continue in effect any provision 
of a safety standard or regulation which prescribes any requirements 
as to the performance, composition, contents, design, finish, 
construction, packaging or labeling of such product which are 
designed to deal with the same risk of injury associated with such 
consumer product, unless such requirements are identical to the 
requirements of the Federal Standard.

15 U.S.C. 2075(a). Thus, the proposed rule would preempt non-identical 
state or local requirements for gas furnaces and boilers designed to 
protect against the same risk of injury, i.e., risk of injury and death 
associated with CO production and leakage from residential gas furnaces 
and boilers.
    States or political subdivisions of a state may apply for an 
exemption from preemption regarding a consumer product safety standard, 
and the Commission may issue a rule granting the exemption if it finds 
that the state or local standard (1) provides a significantly higher 
degree of protection from the risk of injury or illness than the CPSA 
standard, and (2) does not unduly burden interstate commerce. 15 U.S.C. 
2075(c).

XIV. Effective Date

    The Administrative Procedure Act (APA) generally requires that the 
effective date of a rule be at least 30 days after publication of a 
final rule. 5 U.S.C. 553(d). Section 9(g)(1) of the CPSA states that a 
consumer product safety rule shall specify the date such rule is to 
take effect, and that the effective date must be at least 30 days after 
promulgation but cannot exceed 180 days from the date a rule is 
promulgated, unless the Commission finds, for good cause shown, that a 
later effective date is in the public interest and publishes its 
reasons for such finding.
    The Commission preliminarily proposes an effective date of 18 
months after publication of the final rule in the Federal Register. The 
rule would apply to gas furnaces and boilers manufactured after the 
effective date. The effective date of the proposed rule is based on 
staff's assessment that, to comply with the final rule, manufacturers 
would have to:
     Identify and establish contracts with suppliers of CO 
sensing or combustion control devices;
     redesign the impacted gas furnaces and boilers to 
integrate CO sensing or combustion control devices;
     work with gas control and control board manufacturers on 
redesigning gas controls and control boards to properly incorporate 
power and output signals from CO sensing or combustion control devices;
     conduct qualification testing and analysis of CO sensing 
or combustion control devices integrated into impacted appliances;
     retool manufacturing lines to allow for CO sensing or 
combustion control devices to be assembled into impacted appliances;
     incorporate the CO sensing or combustion control devices 
into existing quality control procedures;
     retrain assembly line staff on the redesigned gas 
appliances and retooled manufacturing lines;
     incorporate the CO sensing or combustion control devices 
into the user, maintenance, and installation instruction manuals of 
impacted appliances;
     develop new guidance for distributors and retail outlets 
for the impacted appliances; and

[[Page 73288]]

     test and certify of the new models to voluntary standards 
required in many jurisdictions to meet building codes.

A shorter effective date would likely result in manufacturers being 
unable to produce compliant products or produce enough products to meet 
their typical demand; resulting in a product shortage in the supply 
chain, consumers being denied their preferred product with a loss of 
utility and potentially an additional cost; and quality control issues.
    We note the proposed 18-month effective date is consistent with the 
applicable voluntary standards for gas furnaces, boilers, and wall and 
floor furnaces (i.e., ANSI Z21.13, ANSI Z21.47, and ANSI Z21.86, as 
well as all other ANSI Z21 standards), which typically allow for an 
effective date of 18 months after new standards provisions are 
approved. While the proposed 18-month effective date is a departure 
from the 180-day default effective date required by section 9(g)(1) of 
the CPSA, the Commission preliminarily concludes that there is good 
cause here to set the effective date at 18 months for manufacturers to 
ensure compliance with the proposed performance requirements of the 
rule based on the reasons discussed above. A detailed discussion of the 
justification for the recommended 18 month effective date is available 
in the Staff NPR Briefing Package. The Commission seeks comments on the 
effective date with specific information to support any argument that 
an effective date longer than the 180-day period specified in CPSA 
section 9(g)(1) is or is not justified by good cause, including for the 
reasons preliminarily identified above.

XV. Paperwork Reduction Act

    This proposed rule contains information collection requirements 
that are subject to public comment and review by the Office of 
Management and Budget (OMB) under the Paperwork Reduction Act of 1995 
(PRA). 44 U.S.C. 3501-3520. We describe the provisions in this section 
of the document with an estimate of the annual reporting burden. Our 
estimate includes the time for gathering certificate data and creating 
General Certificates of Conformity (GCC), the keeping and maintaining 
of records associated with the GCCs, and the disclosure of GCCs to 
distributers and retails.
    CPSC particularly invites comments on: (1) whether the collection 
of information is necessary for the proper performance of the CPSC's 
functions, including whether the information will have practical 
utility; (2) the accuracy of the CPSC's estimate of the burden of the 
proposed collection of information, including the validity of the 
methodology and assumptions used; (3) ways to enhance the quality, 
utility, and clarity of the information to be collected; (4) ways to 
reduce the burden of the collection of information on respondents, 
including the use of automated collection techniques, when appropriate, 
and other forms of information technology; and (5) estimated burden 
hours associated with label modification, including any alternative 
estimates.
    Title: Safety Standard for Gas Furnaces and Boilers.
    Description: The proposed rule would require each gas furnace and 
boiler to comply with performance requirements under which the 
appliance shuts off or modulates when CO levels reach specified amounts 
for a certain time duration.
    Description of Respondents: Persons who manufacture or import gas 
furnaces and boilers. Staff estimates the burden of this collection of 
information as follows in Table 2:

                                                       Table 2--Estimated Annual Reporting Burden
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                             Number of     Frequency of    Total annual     Minutes per    Total burden
                       Burden type                          respondents      responses       responses       response          hours        Annual cost
--------------------------------------------------------------------------------------------------------------------------------------------------------
GCC Creation............................................              20             500          10,000               5             833         $63,525
Recordkeeping...........................................              20             500          10,000            1.25             208           7,005
Third Party Disclosure..................................              20             500          10,000              15           2,500          84,200
--------------------------------------------------------------------------------------------------------------------------------------------------------

    Section 14(a)(1) of the CPSA, 15 U.S.C. 2063(a)(1), would require 
manufacturers to certify that their products conform to the proposed 
rule and issue a GCC. There are 20 known corporate entities supplying 
gas furnaces and boilers to the U.S. market. On average, each entity 
may issue 500 certificates for complying gas furnaces or boilers in the 
market. Each manufacturer or importer may issue 500 certificates for a 
total of 10,000 certificates (20 firms times 500 certificates per firm 
= 10,000 certificates). Staff treats each certificate issued as a new 
recordkeeping response so there is a total of 10,000 responses for GCC 
creation. The estimated time required to issue a GCC is estimated at 
about five minutes (although it often could be less). To comply with 
the CPSA, gas furnace and boiler manufacturers covered by the rule must 
subject their products to a reasonable testing program. Quality control 
and testing is usual and customary for gas furnace and boiler 
manufacturers, however creation (i.e., recording of test results) may 
not be. Staff estimates that each firm may spend five minutes per 
certificate issued recording the results of a reasonable testing 
program. This would include the time taken to read the test results, 
create the testing record, and issue a certificate. Therefore, the 
estimated burden associated with issuance of GCCs is 833 hours (10,000 
responses x 5 minutes per response = 50,000 minutes or 833 hours). 
Staff estimates the hourly compensation for the time required to issue 
GCCs is $76.26 (U.S. Bureau of Labor Statistics, ``Employer Costs for 
Employee Compensation,'' March 2023, Table 4, management, business, and 
financial occupations: https://www.bls.gov/news.release/pdf/ecec.pdf). 
Therefore, the estimated annual cost to industry associated with 
issuance of a GCC is $63,525 ($76.26 per hour x 833 hours).
    We estimate for the purpose of this burden analysis that records 
supporting GCC creation, including testing records, would be maintained 
for a five-year period. Staff estimates another 10,000 recordkeeping 
responses, each one of which requires 1.25 minutes per year in routine 
recordkeeping. This adds up to 12,500 minutes or 208 hours. Staff 
estimates the hourly compensation for the time required to issue is 
$33.68 (U.S. Bureau of Labor Statistics, ``Employer Costs for Employee 
Compensation,'' March 2023, Table 4, office and administrative support 
occupations: https://www.bls.gov/news.release/pdf/ecec.pdf). Therefore, 
the estimated annual cost to industry associated with recordkeeping 
associated with GCCs is $7,005 ($33.68 per hour x 208 hours).
    Section 14(g)(3) of the CPSA also requires that GCCs be disclosed 
to third party retailers and distributors. Staff estimates another 
10,000 third party disclosure responses, each one of which

[[Page 73289]]

requires 15 minutes per year. This adds up to 150,000 minutes (10,000 
responses x 15 minutes per response) or 2,500 hours. Staff uses an 
hourly compensation for the time required to disclose certificates to 
third parties of $33.68 (U.S. Bureau of Labor Statistics, ``Employer 
Costs for Employee Compensation,'' March 2023, Table 4, office and 
administrative support occupations: https://www.bls.gov/news.release/pdf/ecec.pdf). Therefore, the estimated annual cost to industry 
associated with third party disclosure of GCCs is $84,200 ($33.68 per 
hour x 2,500 hours). There are no operating, maintenance, or capital 
costs associated with the collection.
    Based on this analysis, the proposed standard for gas furnaces and 
boilers would impose a total paperwork burden to industry of 4,374 
hours (833 hours + 833 + 208 hours + 2,500 hours), at an estimated cost 
of $154,730 annually ($63,525 + $7,005 + $84,200). Existing gas furnace 
and boiler manufactures would incur these costs in the first year 
following the proposed rule's effective date. In subsequent years, 
costs could be less, depending on the number of new GCCs issued for gas 
furnaces and boilers. As required under the PRA (44 U.S.C. 3507(d)), 
CPSC has submitted the information collection requirements of this 
proposed rule to the OMB for review. Interested persons are requested 
to submit comments regarding information collection by December 26, 
2023, to the Office of Information and Regulatory Affairs, OMB as 
described under the ADDRESSES section of this notice.

XVI. Certification

    Section 14(a)(1) of the CPSA requires that products subject to a 
consumer product safety rule under the CPSA, or to a similar rule, ban, 
standard or regulation under any other act enforced by the Commission, 
must be certified with a GCC as complying with all applicable CPSC-
enforced requirements. 15 U.S.C. 2063(a). A final rule would subject 
gas furnaces and boilers to this requirement.

XVII. Promulgation of a Final Rule

    Section 9(d)(1) of the CPSA requires the Commission to promulgate a 
final consumer product safety rule within 60 days of publishing a 
proposed rule. Otherwise, the Commission must withdraw the proposed 
rule if it determines that the rule is not reasonably necessary to 
eliminate or reduce an unreasonable risk of injury associated with the 
product or is not in the public interest. However, the Commission can 
extend the 60-day period, for good cause shown, if it publishes the 
reasons for doing so in the Federal Register. 15 U.S.C. 2058(d)(1).
    The Commission finds that there is good cause to extend the 60-day 
period for this rulemaking. Under both the APA and the CPSA, the 
Commission must provide an opportunity for interested parties to submit 
written comments on a proposed rule. 5 U.S.C. 553; 15 U.S.C. 
2058(d)(2). The Commission is providing 60 days for interested parties 
to submit written comments. A shorter comment period may limit the 
quality and utility of information CPSC receives, particularly for 
areas where it seeks data and other detailed information that may take 
time for commenters to compile. Additionally, the CPSA requires the 
Commission to provide interested parties with an opportunity to make 
oral presentations of data, views, or arguments. 15 U.S.C. 2058. This 
may require time for the Commission to arrange a public meeting for 
this purpose and provide notice to interested parties in advance of 
that meeting. After receiving written and oral comments, CPSC staff 
must have time to review and evaluate those comments.
    These factors make it impractical for the Commission to issue a 
final rule within 60 days of this proposed rule. Accordingly, the 
Commission finds that there is good cause to extend the 60-day period 
for promulgating the final rule after publication of the proposed rule.

XVIII. Request for Comments

    We invite all interested persons to submit comments on all aspects 
of the proposed rule. The Commission particularly seeks comment on the 
following items:
     the CO concentration and associated time thresholds in the 
proposed performance requirements;
     the proposed fail safe provisions in the performance 
requirement;
     the efficacy of the proposed fail safe provisions and 
whether there is a more appropriate approach to address fail safe;
     should the proposed performance requirement include an 
audible alarm notification requirement that indicates when a gas 
furnace or boiler exceeds the proposed CO limits or when a CO sensor is 
no longer working properly;
     effort required to obtain sensors and information on 
sensors including the lifespan;
     effort required to redesign control systems;
     effort required to test prototypes;
     effort required to bring re-engineered appliances to 
production;
     costs associated with an effective date six months after 
publication of the rule;
     costs associated with an effective date 30 days after 
publication of the rule;
     costs associated with shipping and inventory of gas 
furnaces and boilers;
     costs associated with manufacturing gas furnaces and 
boilers, along with a description of the process including the timing 
and whether any firms have seasonal production;
     under the proposed stockpiling provision should zero-
production months be averaged in to maintain a roughly constant level 
of supply for a seasonally produced product to avoid dramatic 
stockpiling if the manufacturer converted to constant production;
     effort required to incorporate sensors and/or combustion 
control systems in production;
     data or information on research and development and 
modifications to the production process the proposed rule would impose 
on manufacturers;
     data or information on price elasticity for gas furnaces 
or boilers;
     additional manufacturers and importers of gas furnaces and 
boilers that may meet the Small Business Administration (SBA) 
definition of a small business;
     information on importers of gas furnaces and gas boilers, 
specifically:
    [cir] how many are imported;
    [cir] how many different models each importer sells; and
    [cir] what technologies those models are currently using 
(atmospheric venting, condensing, non-condensing, premix power burners, 
etc.); and
     information regarding the degree to which supplying firms 
are able to pass on increases in production and regulatory costs to 
importers.

XIX. Notice of Opportunity for Oral Presentation

    Section 9 of the CPSA requires the Commission to provide interested 
parties ``an opportunity for the oral presentation of data, views, or 
arguments.'' 15 U.S.C. 2058(d)(2). The Commission must keep a 
transcript of such oral presentations. Id. Any person interested in 
making an oral presentation must contact the Commission, as described 
under the DATES and ADDRESSES section of this notice.

List of Subjects in 16 CFR Part 1408

    Administrative practice and procedure, Consumer protection, 
Incorporation by reference, Gas furnaces and boilers.


[[Page 73290]]



0
For the reasons discussed in the preamble, the Commission proposes to 
amend Title 16 of the Code of Federal Regulations by adding a new part 
to read as follows:

PART 1408--SAFETY STANDARD FOR RESIDENTAL GAS FURNACES AND BOILERS

Sec.
1408.1 Scope, purpose, and effective date.
1408.2 Definitions.
1408.3 Performance requirements for residential gas furnaces and 
boilers.
1408.4 Incorporation by reference.
1408.5 Prohibited stockpiling.
Appendix A--Preliminary Findings Under the Consumer Product Safety 
Act

    Authority:  15 U.S.C. 2056, 15 U.S.C. 2058, and 5 U.S.C. 553.


Sec.  1408.1  Scope, purpose, and effective date.

    This part establishes performance requirements for residential gas 
furnaces, boilers, and wall and floor furnaces (gas furnaces and 
boilers) that are consumer products used to heat dwellings, including 
but not limited to, single family homes, townhomes, condominiums, and 
multifamily dwellings, as well as multi-family buildings such as 
apartments and condominiums. The purpose of these requirements is to 
reduce the occurrence of carbon monoxide-related deaths, injuries, and 
exposures associated with gas furnaces and boilers. All residential gas 
furnaces and boilers manufactured after [DATE 18 MONTHS AFTER 
PUBLICATION OF THE FINAL RULE IN THE FEDERAL REGISTER] must meet the 
requirements of this part.


Sec.  1408.2  Definitions.

    Gas Central Furnace means a gas-burning appliance that heats air by 
the transfer of heat of combustion through a heat exchanger and 
supplies heated air through ducts to spaces remote from or adjacent to 
the appliance location.
    Gas Floor Furnace means a furnace suspended between the floor 
joists of the space being heated. A floor furnace provides direct 
heating of the room in which it is located and to adjacent rooms.
    Gas Steam and Hot Water Boiler means a gas burning appliance that 
heats steam at a pressure not exceeding 15 psi (100 kPa), or hot water 
at a pressure not exceeding 160 psi (1100 kPa) and at a temperature not 
exceeding 250 [deg]F (121 [deg]C). The heated steam or water is pumped 
to spaces remote from or adjacent to the appliance location through 
piping to radiators, where the heat of combustion is transferred to 
heat the air around the radiator.
    Gas Wall Furnace means a gas appliance installed within a wall that 
provides heated air directly to the room in which it is installed and 
to adjacent rooms through grilles.


Sec.  1408.3  Performance requirements for residential gas furnaces and 
boilers.

    (a) General. All residential vented gas furnaces, boilers, wall 
furnaces, and floor furnaces must have a means to either directly or 
indirectly monitor the concentration of carbon monoxide (CO) produced 
during the combustion process (i.e., ``CO emissions''), and shut down 
or modulate combustion to reduce average CO concentrations to below the 
CO levels for the durations of time specified in paragraph (b) of this 
section. If the average CO emissions reach or exceed the CO limits and 
time durations specified in paragraph (b), then the gas furnace or 
boiler must either shut down or modulate combustion to reduce average 
CO emissions to below 150 ppm. If average CO levels range between 200 
and 299 ppm for 50 minutes, then the gas furnace or boiler must either 
shut down or modulate combustion to reduce average CO emissions to 
below 150 ppm. If average CO levels range between 300 and 399 ppm for 
40 minutes, then the gas furnace or boiler must either shut down or 
modulate combustion to reduce average CO emissions to below 150 ppm. If 
average CO levels range between 400 and 499 ppm for 30 minutes, then 
the gas furnace or boiler must either shut down or modulate combustion 
to reduce average CO emissions to below 150 ppm. If average CO levels 
range from 500 ppm or higher for 15 minutes, then the gas furnace or 
boiler must either shut down or modulate combustion to reduce average 
CO emissions to below 150 ppm. Indirect monitoring and control of CO 
emissions can be accomplished by monitoring and controlling other 
combustion parameter(s) that accurately correlate to the production of 
CO. Examples of parameters that can serve as a proxy for CO production 
include carbon dioxide (CO2), oxygen (O2), the 
Gas/Air Ratio, and the flame ionization current produced by the burner 
flame.
    (b) Performance requirements for gas furnaces and boilers. A gas 
furnace, boiler, wall furnace, or floor furnace must be equipped with a 
means to continuously monitor CO emission and must meet the 
requirements using one of the methods described in either paragraph 
(b)(1)(i) or paragraph (b)(2)(i) for the multipoint method or paragraph 
(b)(1)(ii) or (b)(2)(ii) for the single point method of this section 
when tested using the test method described in paragraph (d) of this 
section.
    (1) Direct means to monitor CO emissions. (i) Multipoint method. A 
gas furnace, boiler, wall furnace, or floor furnace equipped with a 
means to directly monitor CO emissions, must either cause shut down of 
the gas furnace or boiler or cause modulation of the gas furnace or 
boiler combustion, in response to the following conditions within the 
gas furnace or boiler:
    (A) average CO concentration is 500 ppm or higher for 15 minutes;
    (B) average CO concentration between 400 ppm and 499 ppm for 30 
minutes;
    (C) average CO concentration between 300 ppm and 399 ppm for 40 
minutes;
    (D) average CO concentration between 200 ppm and 299 ppm for 50 
minutes;
    (E) average CO concentration between 150 and 199 ppm for 60 
minutes.
    (ii) Single point method. A manufacturer may use the single point 
method instead of the multipoint method described in paragraph 
(b)(1)(i) for a gas furnace, boiler, wall furnace, or floor furnace 
equipped with a means to directly monitor CO emissions; which must 
either cause shut down of the gas furnace or boiler or cause modulation 
of the gas furnace or boiler combustion, in response to the following 
conditions within the gas furnace or boiler:
    (A) Average CO concentration of 150 ppm or higher for 15 minutes. 
Shutdown or modulation of the gas furnace or boiler must begin 
immediately after any of the conditions described in paragraphs 
(b)(1)(i)(A) through (E) are reached or the alternative condition 
described in paragraph (b)(1)(ii)(A) is reached. After modulation 
begins, the CO concentration within the gas furnace or boiler must be 
reduced to below 150 ppm within 15 minutes.
    (B) [Reserved]
    (2) Indirect means to monitor CO emissions. (i) Multipoint method. 
A gas furnace, boiler, wall furnace, or floor furnace equipped with an 
indirect means to monitor CO emissions, must either cause shut down of 
the gas furnace or boiler or cause modulation of combustion of the gas 
furnace or boiler, each in response to the combustion conditions that 
correlate to the following conditions within the gas furnace or boiler:
    (A) average CO concentration is 500 ppm or higher for 15 minutes;
    (B) average CO concentration between 400 ppm and 499 ppm for 30 
minutes;
    (C) average CO concentration between 300 ppm and 399 ppm for 40 
minutes;
    (D) average CO concentration between 200 ppm and 299 ppm for 50 
minutes;

[[Page 73291]]

    (E) average CO concentration between 150 and 199 ppm for 60 
minutes.
    (ii) Single Point method. A manufacturer may use the single point 
method instead of the multipoint method described in paragraph 
(b)(2)(i) for a gas furnace, boiler, wall furnace, or floor furnace 
equipped with a means to indirectly monitor CO emissions, which must 
either cause shut down of the gas furnace or boiler or cause modulation 
of combustion within the gas furnace or boiler, in response to the 
following condition within the gas furnace or boiler:
    (A) Average CO concentration of 150 ppm or higher for 15 minutes. 
Shutdown or modulation of the gas furnace or boiler must begin 
immediately after any of the conditions described in paragraphs 
(b)(2)(i)(A) through (E) are reached or the alternative condition 
described in paragraph (b)(2)(ii)(A) is reached. After modulation 
begins, the CO concentration within the gas furnace or boiler must be 
reduced to below 150 ppm within 15 minutes.
    (B) [Reserved]
    (3) Fail Safe. During the life of the gas furnace or boiler, if a 
CO sensor, combustion sensor, combustion control system, or other 
device designed to meet these requirements fails to operate properly or 
at all, then the gas furnace or boiler must shutdown and restart after 
15 minutes and repeat this cycle until the failed component is 
replaced. Consumers and service technicians must be notified of device 
failure by either a flashing light or other appropriate code on the gas 
furnace or boiler control board that corresponds to the device failure.
    (c) Test Configuration. Gas furnace or boilers must be configured 
in the following manner for testing. Gas Furnaces, boilers, wall 
furnaces, and floor furnaces must each be set up with the burner and 
primary air adjusted in accordance with the provisions of the 
Combustion sections of the respective voluntary standards (section 
5.8.1 of ANSI Z21.47-2021 for gas furnaces; section 5.5.1 of ANSI 
Z21.13-2022 for gas boilers; and sections 9.3.1, 11.2.1, and 13.3.1, of 
ANSI Z21.86-2016 for gas wall and floor furnaces). These tests must be 
conducted in an atmosphere having normal oxygen supply of approximately 
20.94 percent. Burner and primary air adjustments must be made for 
furnaces, boilers, wall furnaces, and floor furnaces in accordance with 
the provisions of each respective standard (section 5.5.4 of ANSI 
Z21.47-2021 for gas furnaces; section 5.3.1 of ANSI Z21.13-2022 for gas 
boilers; and section 2.3.4 of ANSI Z21.86-16 for gas wall and floor 
furnaces). After adjustment, and with all parts of the furnace, boiler, 
wall furnace, or floor furnace at room temperature, the pilot(s), if 
provided, must be placed in operation and allowed to operate for a 
period of five minutes. The main burner(s) must then be placed in 
operation and the gas furnace or boiler operated for three minutes at 
normal inlet test pressure at which time a sample of the flue gases 
must be secured. Immediately upon securing the sample at normal inlet 
test pressure, the reduced inlet test pressure (section 5.5.1 of ANSI 
Z21.47:2021; section 5.3.1 of ANSI Z21.13-2022; and section 2.3.1 of 
ANSI Z21.86-16) must be applied and, following a purge period of at 
least two minutes, another sample of the flue gases must be secured. 
For atmospheric burner units, samples must be secured at a point 
preceding the inlet to the unit's draft hood or flue outlet where 
uniform samples can be obtained. The flue gas sample must be analyzed 
for carbon dioxide and carbon monoxide. The average concentration of 
carbon monoxide for the flue gas samples must not exceed 150 ppm in a 
sample of flue gases after 15 minutes.
    (d)(1) Test Procedure. To test a furnace, boiler, wall furnace, or 
floor furnace to the performance requirements specified in paragraph 
(b) of this section, induce the production of CO or related combustion 
parameters, one or a combination of the following methods must be used:
    (i) Progressively increase the gas control valve's outlet pressure 
until the unit produces a CO concentration of approximately 150 ppm 
10 ppm CO. For natural gas units, use a propane conversion 
kit to achieve the desired CO concentration if this was not 
accomplished by increasing the gas valve's outlet pressure. For propane 
units, use either option in paragraph (b)(2)(i)(B) or (C). If neither 
option results in a CO concentration of approximately 150 ppm, then use 
both options in paragraphs (b)(3)(i)(B) and (C). Once a CO 
concentration of at least 150 ppm is achieved, that condition must be 
maintained for 15 minutes.
    (ii) Progressively block the exhaust vent or flue outlet until the 
unit produces approximately 150 ppm 10 ppm CO. Disable the 
unit's blocked vent shutoff switch (BVSS) if necessary, in order to 
achieve the desired CO concentration. Once a CO concentration of 
approximately 150 ppm is achieved, that condition must be maintained 
for 15 minutes.
    (iii) Reduce the fan speed of the inducer motor or premix power 
burner (for induced draft or premix power burner units only) by 
reducing the supply voltage to 85 percent of the gas furnace or boiler 
rating plate voltage until the unit produces a CO concentration of 
approximately 150 ppm 10 ppm CO. An additional combustion 
sample must be secured with the gas furnace or boiler operating at 
normal inlet test pressure and with the supply voltage reduced to 85 
percent of the gas furnace or boiler rating plate voltage. This sample 
must be secured 15 minutes after the furnace has operated at the 
reduced voltage. The input rating may vary from normal as a result of 
the voltage reduction. Once a CO concentration of approximately 150 ppm 
is achieved, that condition must be maintained for 15 minutes.
    For gas furnaces and boilers that employ modulation (e.g., using a 
Gas/Air Ratio Controller, an automatic step-rate control, or automatic 
modulating controls, etc.) the unit must immediately begin modulation 
to reduce the CO concentration to below 150 ppm. For gas furnaces and 
boilers that do not employ modulation, the unit must shut down.
    (2) Time for shutoff using multipoint method or modulation. The 
time for the gas to the main burner(s) to be shut off or begin 
modulation by the device used to directly or indirectly monitor CO 
emissions must be:
    (i) After 15 minutes at an average CO concentration of 500 ppm or 
more.
    (ii) After 30 minutes at an average CO concentration of 400-499 
ppm.
    (iii) After 40 minutes at an average CO concentration of 300-399 
ppm.
    (iv) After 50 minutes at an average CO concentration of 200-299 
ppm.
    (v) After 60 minutes at an average CO concentration of 150-199 ppm.
    (3) Time for shutoff using single point method or modulation. A 
manufacturer, instead of using the multipoint method describe in 
paragraph (d)(2) may use the following single point conditions and time 
to shut off the gas furnace or boiler or begin modulation in response 
to the following condition within the gas furnace or boiler:
    (i) Average CO concentration of 150 ppm or higher for 15 minutes. 
Shutdown or modulation of the appliance shall begin immediately after 
any of the conditions described in paragraph (d)(2) is reached. After 
modulation begins, the CO concentration within the appliance shall be 
reduced to below 150 ppm within 15 minutes.
    (ii) [Reserved]


Sec.  1408.4   Incorporation by reference.

    Certain material is incorporated by reference into this part with 
the

[[Page 73292]]

approval of the Director of the Federal Register in accordance with 5 
U.S.C. 552(a) and 1 CFR part 51. All approved incorporation by 
reference (IBR) material is available for inspection at the Consumer 
Product Safety Commission and at the National Archives and Records 
Administration (NARA). Contact the U.S. Consumer Product Safety 
Commission at: Office of the Secretary, U.S. Consumer Product Safety 
Commission, 4330 East-West Highway, Bethesda, MD 20814; telephone (301) 
504-7479; email [email protected]. For information on the availability 
of this material at NARA, visit www.archives.gov/federal-register/CFR/IBR-locations.html or email [email protected]. The following 
material may be obtained from the Canadian Standards Association, 8501 
East Pleasant Valley Road, Independence, OH 44131-5516: 1-800-463-6727; 
www.csagroup.org/store/:
    (a) ANSI Z21.13-2022, Standard: Gas-fired low-pressure steam and 
hot water boilers, published August 2022.
    (b) ANSI Z21.47-2021, Standard: Gas-fired central furnaces, 
published May 2021.
    (c) ANSI Z21.86-2016, Standard: Vented gas-fired space heating 
appliances, published January 2017.


Sec.  1408.5   Prohibited stockpiling.

    (a) Prohibited acts. Manufacturers and importers of gas furnaces, 
boilers, wall furnaces, and floor furnaces shall not manufacture or 
import products that do not comply with the requirements of this part 
between [DATE OF PUBLICATION OF FINAL RULE] and [EFFECTIVE DATE OF 
FINAL RULE] at a rate greater than 106 percent of the base period in 
the first 12 months after promulgation of the rule, and 112.50 percent 
of the base period for the remaining six months until the effective 
date for the rule.
    (b) Base period. The base period for gas furnaces, boilers, wall 
furnaces, and floor furnaces is the calendar month with the median 
manufacturing or import volume within the last 13 months immediately 
preceding the month of promulgation of the final rule.

Appendix A to Part 1408--Preliminary Findings Under the Consumer 
Product Safety Act

    The Consumer Product Safety Act requires that the Commission, in 
order to issue a standard, make the following findings and include 
them in the rule. 15 U.S.C. 2058(f)(3).

A. Degree and Nature of the Risk of Injury

    The Commission proposes this rule to reduce the risk of death 
and injury associated with CO production and leakage from 
residential gas furnaces, boilers, wall furnaces, and floor 
furnaces. Between 2017 to 2019 (the most recent period for which 
data are complete), there were annually an estimated 21 CO deaths 
associated with residential gas furnaces and boilers. For the 20-
year period 2000 through 2019, these products were associated with a 
total of 539 CO deaths. Between the years 2014 and 2018, 236 
nonfatal injuries were reported through the National Electronic 
Injury Surveillance System (NEISS) related to CO leakages from gas 
furnaces and boilers. Staff used NEISS incidents and the Injury Cost 
Model to extrapolate and generate national estimates for injuries 
from CO leakages from gas furnaces and boilers with 30,587 nonfatal 
injuries from CO leakages from 2014 to 2018.

B. Number of Consumer Products Subject to the Rule

    An estimated 70 firms manufacturer residential gas furnaces and 
boilers. When accounting for subsidiaries and multiple brands 
provided by the same company, 20 parent manufacturers have been 
identified. In 2020, there was an estimated 60.94 million total 
number of residential gas furnaces and boilers in use. In 2021 
residential gas furnace sales were estimated to be 3.58 million 
units, and 0.30 million units for gas boilers.

C. Need of the Public for the Products and Probable Effect on Utility, 
Cost, and Availability of the Product

    (1) Residential gas furnaces and boilers are fueled by natural 
gas or propane (gas) and are used to heat all categories of 
residential dwellings, including single family homes, townhomes, 
condominiums, and multifamily dwellings, as well as small-to medium-
sized commercial dwellings. Because the rule is a performance 
standard that allows for the sale of compliant gas furnaces and 
boilers, it is not expected to have an impact on the utility of the 
product.
    (2) The cost of compliance to address CO hazards include 
increased variable costs of producing furnaces and boilers with CO 
sensors and shutoff capabilities; one-time conversion costs of 
redesigning and modifying factory operations for installing CO 
sensors; increased maintenance costs of gas furnaces and boilers to 
consumers, and deadweight loss in the market caused by the 
increasing price due to regulation and the subsequent decline in 
sales. Staff performed a 30-year prospective cost assessment (2025-
2054) on all four cost categories and estimated the total annualized 
cost from the proposed rule to be $602.27 million, discounted at 
three percent. Staff estimated the per-unit (of a gas furnace or 
boiler) costs from the proposed rule to be $158.11, discounted at 
three percent.
    Dead weight loss refers to the lost producer and consumer 
surplus from reduced quantities of gas furnaces and boilers sold and 
used due to the rule-induced increases in manufacturer cost and 
retail price. Producer surplus represents the difference between the 
amount a producer is willing to sell a good or service for and the 
price they actually receive. Consumer surplus represents the benefit 
that consumers receive from purchasing a good or service at a price 
that is lower than their willingness to pay. For those units no 
longer produced due to the rule, suppliers lose out on the producer 
surplus associated with those units, and consumers lose out on the 
consumer surplus associated with those units.
    In the first year, producer manufacturing costs are expected to 
increase by $22.08 per gas furnace causing a $70.44 per unit in 
higher retail costs to the consumer in the form of higher retail 
prices. Gas boiler manufacturing costs are expected to increase by 
$26.54 per unit causing an $87.59 in higher retail costs to the 
consumer. The resultant decrease in the number of gas furnaces and 
boilers sold and used is expected to generate a dead weight loss of 
about $1 million per year nationwide.
    (3) Staff does not expect that the availability of gas furnaces 
and boilers will be substantially impacted by the rule. Staff 
estimates baseline (status quo) sales of 3.96 million units of gas 
furnaces and boilers in 2025 which in the absence of the rule, would 
grow to 4.72 million by 2054. With the promulgation of the rule 
staff expects gas furnace and boiler sales of 3.92 million units in 
2025 would grow to 4.69 million units by 2054.

D. Any Means To Achieve the Objective of the Rule, While Minimizing 
Adverse Effects on Competition and Manufacturing

    (1) The rule reduces CO hazards associated with residential gas 
furnaces and boilers while minimizing the effect on competition and 
manufacturing. Manufacturers can transfer some, or all, of the 
increased production cost to consumers through price increases. At 
the margins, some producers may exit the market because their 
increased marginal costs now exceed the increase in market price. 
Likewise, a very small fraction of consumers may be excluded from 
the market if the increased market price exceeds their personal 
price threshold for purchasing a gas furnace or boiler. However, the 
Commission did not find any information or assessment that would 
suggest significant changes to market competition or composition.
    (2) The Commission considered alternatives to the rule to 
minimize impacts on competition and manufacturing including: (1) 
continuing to work and advocate for change through the voluntary 
standards process; (2) relying on the use of residential CO alarms; 
(3) continuing to conduct education and information campaigns; and 
(4) relying on recalls. The Commission determines that none of these 
alternatives would adequately reduce the risk of deaths and injuries 
associated with the CO hazards presented by residential gas furnaces 
and boilers.

E. The Rule (Including Its Effective Date) Is Reasonably Necessary To 
Eliminate or Reduce an Unreasonable Risk of Injury

    Between 2000 and December 2019, incident data show 539 fatal 
incidents related to CO hazards associated with gas furnaces and 
boilers. The incident data show that these incidents continue to 
occur and are likely to increase because the existing ANSI voluntary 
standards do not have requirements that would adequately reduce

[[Page 73293]]

the CO hazard presented by gas furnaces and boilers and the market 
for gas furnaces and boilers is forecast to grow. The rule 
establishes performance requirements to address the risk of CO 
poisoning associated with residential gas furnaces and boilers. The 
effective date provides a reasonable amount of time for 
manufacturers to comply with the rule and produce products that 
prevent the CO hazard. Given the deaths and injuries associated with 
CO leakage from gas furnaces and boilers, the Commission finds that 
the rule and its effective date are necessary to address the 
unreasonable risk of injury associated with gas furnaces and 
boilers.

F. Public Interest

    The rule addresses an unreasonable risk of death and injuries 
presented from CO hazards associated with gas furnaces and boilers. 
Adherence to the requirements of the rule would reduce deaths and 
injuries from CO poisoning associated with gas furnaces and boilers; 
thus, the rule is in the public interest.

G. Voluntary Standards

    If a voluntary standard addressing the risk of injury has been 
adopted and implemented, then the Commission must find that the 
voluntary standard is not likely to eliminate or adequately reduce 
the risk of injury or substantial compliance with the voluntary 
standard is unlikely. The Commission determines that the relevant 
U.S. voluntary standards (ANSI Z21.13-2022, ANSI Z21.47-2021, and 
ANSI Z21.86-2016) do not contain performance requirements to protect 
against the known failure modes or conditions identified that have 
been associated with the production and leakage of CO into living 
spaces of U.S. residences resulting in numerous deaths and injuries, 
and thus do not adequately address the hazard of CO exposure from 
residential gas furnaces and boilers.

H. Reasonable Relationship of Benefits to Costs

    The Commission determines the benefits expected from the rule 
bear a reasonable relationship to its costs. The rule significantly 
reduces the CO hazard associated with residential gas furnaces and 
boilers, and thereby reduces the societal costs of the resulting 
injuries and deaths. When costs are compared to benefits, the 
estimated costs of the rule are greater than the estimated benefits. 
Staff calculates net benefits (benefits less costs) to be -$245.74 
million on annualized basis, discounted at three percent. The net 
benefits on per-unit basis are -$64.51, discounted at three percent. 
Alternatively, this can be described as the proposed rule being a 
net cost of -64.51 per gas furnace or boiler, which represents 
approximately three percent of the average price of a gas furnace or 
boiler. Overall, the proposed rule has a benefit-cost ratio of 0.59; 
in other words, for every $1 in cost of the proposed rule, there is 
a return of $0.59 in benefits from mitigated deaths and injuries. 
However, the rule is estimated to address 90-100 percent of deaths 
caused by the CO hazard associated with gas furnaces and boilers, 
resulting in potential total societal annualized benefits from the 
rule of $356.52 million, discounted at three percent. Staff 
conducted a sensitivity analysis that showed if by 2035 
manufacturers were able to develop compliant gas furnaces and 
boilers with CO sensors that did not need replacement, and if the 
analysis took into account that a child's death is considered twice 
as costly as an adult death, the benefit-cost ratio would increase 
to 0.78.

I. Least-Burdensome Requirement That Would Adequately Reduce the Risk 
of Injury

    The Commission considered four alternatives to the proposed 
rule: (1) continue to work and advocate for change through the 
voluntary standards process; (2) rely on the use of residential CO 
alarms; (3) continue to conduct education and information campaigns; 
and (4) rely on recalls. Although these alternatives may be less 
burdensome alternatives to the rule, the Commission determines that 
none of the alternatives would adequately reduce the risk of deaths 
and injuries associated with gas furnaces and boilers that is 
addressed by the rule.

Elina Lingappa,
Paralegal Specialist, Consumer Product Safety Commission.

[FR Doc. 2023-23302 Filed 10-24-23; 8:45 am]
BILLING CODE 6355-01-P