Hazardous Materials; Packages Intended for Transport by Aircraft, 27273-27284 [2010-11384]

Agencies

• Pipeline and Hazardous Materials Safety Administration
• DEPARTMENT OF TRANSPORTATION

[Federal Register Volume 75, Number 93 (Friday, May 14, 2010)]
[Proposed Rules]
[Pages 27273-27284]
From the Federal Register Online via the Government Printing Office [www.gpo.gov]
[FR Doc No: 2010-11384]


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DEPARTMENT OF TRANSPORTATION

Pipeline and Hazardous Materials Safety Administration

49 CFR Parts 171 and 173

[Docket No. PHMSA-07-29364 (HM-231A)]
RIN 2137-AE32


Hazardous Materials; Packages Intended for Transport by Aircraft

AGENCY: Pipeline and Hazardous Materials Safety Administration (PHMSA), 
DOT.

ACTION: Notice of proposed rulemaking (NPRM).

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SUMMARY: PHMSA proposes to amend requirements in the Hazardous 
Materials Regulations to enhance the integrity of inner packagings or 
receptacles of combination packagings containing liquid hazardous 
material by ensuring they remain intact when subjected to the reduced 
pressure and other forces encountered in air transportation. In order 
to substantially decrease the likelihood of a hazardous materials 
release, the proposed amendments: prescribe specific test protocols and 
standards for determining whether an inner packaging or receptacle is 
capable of meeting the pressure differential requirements specified in 
the regulations and, consistent with the 2011-2012 edition of the 
International Civil Aviation Organization Technical Instructions for 
the Safe Transport of Dangerous Goods by Aircraft (ICAO Technical 
Instructions), require the closures on all inner packagings containing 
liquids within a combination packaging to be secured by a secondary 
means or, under certain circumstances, permit the use of a liner.

DATES: Comments must be received by July 13, 2010.

ADDRESSES: You may submit comments identified by the docket number 
PHMSA-07-29364 (HM-231A) by any of the following methods:
     Federal eRulemaking Portal: Go to https://www.regulations.gov. Follow the online instructions for submitting 
comments.
     Fax: 1-202-493-2251.
     Mail: Docket Operations, U.S. Department of 
Transportation, West Building, Ground Floor, Room W12-140, Routing 
Symbol M-30, 1200 New Jersey Avenue, SE., Washington, DC 20590.
     Hand Delivery: To Docket Operations, Room W12-140 on the 
ground floor of the West Building, 1200 New Jersey Avenue, SE., 
Washington, DC 20590, between 9 a.m. and 5 p.m., Monday through Friday, 
except Federal Holidays.
    Instructions: All submissions must include the agency name and 
docket number for this notice at the beginning of the comment. Note 
that all comments received will be posted without change to the docket 
management system, including any personal information provided.
    Docket: For access to the dockets to read background documents or 
comments received, go to https://www.regulations.gov or DOT's Docket 
Operations Office (see ADDRESSES).
    Privacy Act: Anyone is able to search the electronic form of any 
written communications and comments received into any of our dockets by 
the name of the individual submitting the document (or signing the 
document, if submitted on behalf of an association, business, labor 
union, etc.). You may review DOT's complete Privacy Act Statement in 
the Federal Register published on April 11, 2000 (Volume 65, Number 70; 
Pages 19477-78).

FOR FURTHER INFORMATION CONTACT: Michael G. Stevens, Office of 
Hazardous Materials Standards, Pipeline and Hazardous Materials Safety 
Administration, U.S. Department of Transportation, 1200 New Jersey 
Avenue, SE., Washington, DC 20590-0001, telephone (202) 366-8553, or 
Janet McLaughlin, Office of Security and Hazardous Materials, Federal 
Aviation Administration, U.S. Department of Transportation, 490 
L'Enfant Plaza, SW., Room 2200, Washington, DC 20024, telephone (202) 
385-4897.

SUPPLEMENTARY INFORMATION:

Contents

I. Background
II. Problem
III. ANPRM
    A. Studies and Data
    B. Pressure Differential Testing
    C. Alternatives to Testing
    D. Packaging Components
IV. Summary of Proposals in This NPRM
    A. Incorporation of Revised ICAO TI Packaging Provisions
    B. Enhanced Pressure Differential Capability Standard
    C. Combined Enhanced Pressure Differential Capability Standard 
and Incorporation of Revised ICAO TI Packaging Provisions
    D. Vibration Testing
V. Regulatory Analyses and Notices

[[Page 27274]]

    A. Statutory/Legal Authority for This Rulemaking
    B. Executive Order 12866 and DOT Regulatory Policies and 
Procedures
    C. Executive Order 13132
    D. Executive Order 13175
    E. Regulatory Flexibility Act, Executive Order 13272, and DOT 
Regulatory Policies and Procedures
    F. Unfunded Mandates Reform Act
    G. Paperwork Reduction Act
    H. Regulatory Identifier Number (RIN)
    I. Environmental Assessment
    J. Privacy Act

I. Background

    The Hazardous Materials Regulations (HMR; 49 CFR parts 171-180) 
authorize a variety of packaging types for the transportation of 
hazardous materials in commerce. Combination packagings are the most 
common type of packaging used for the transportation of both liquid and 
solid hazardous materials by aircraft. A combination packaging consists 
of one or more inner packagings or one or more articles secured in a 
non-bulk outer packaging.\1\
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    \1\ As a receptacle for a liquid or solid, a non-bulk outer 
packaging is one that has a maximum capacity of 450 liters (119 
gallons) and, for solid contents, a maximum net mass of 400 kg (882 
pounds). Sec.  171.8.
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    Requirements for combination packagings used to transport hazardous 
materials are set forth in parts 173 and 178 of the HMR. Certain 
classes and quantities of hazardous materials may be transported in 
``non-UN standard'' combination packagings, which are subject only to 
the general requirements in subpart B of part 173, including the 
following:

--The packaging must be designed, constructed, filled, and closed so 
that it will not release its contents under conditions normally 
incident to transportation. Sec.  173.24(b)(1).
--The effectiveness of the package must be maintained to withstand 
minimum and maximum temperatures, changes in humidity and pressure, and 
shocks, loadings and vibrations normally encountered during 
transportation. Sec.  173.24(b)(2).
-- Each non-bulk packaging must be capable of withstanding, without 
rupture or leakage, the vibration test procedure specified in Sec.  
178.608 of this subchapter, which sets forth a specific test method to 
measure the vibration capability of a non-bulk packaging. Sec.  
173.24a(a)(5).

    A packaging authorized for transportation by aircraft must also be 
designed and constructed to prevent leakage that may be caused by 
changes in altitude and temperature. Sec.  173.27(c)(1). Inner 
packagings of combination packagings for which retention of liquid is a 
basic function must be capable of withstanding the greater of: (1) An 
internal pressure that produces a gauge pressure of not less than 75 
kPa for liquids in Packing Group III of Class 3 or Division 6.1 and 95 
kPa for other liquids; or (2) a pressure related to the vapor pressure 
of the liquid to be transported as determined by specified formulae. 
Sec.  173.27(c). A number of voluntary industry consensus standards 
have been developed, some of which include test methods intended to 
evaluate the effects of pressure differential on packagings at the 
various altitudes experienced in the air transport environment. These 
standards-setting organizations have also conducted measurement studies 
and testing to identify the transportation forces a package encounters 
and developed integrity standards and industry best-practices to ensure 
the pressure differential capability standard is met. This process 
assists all parties to design and manufacture packaging with quality 
standards that could be used to verify conformance with capability 
requirements. However, these voluntary industry standards are not 
included or referenced in the HMR, and the HMR do not provide specific 
guidance to shippers or packaging manufacturers as to how to comply 
with the pressure differential standards.
    Subparts L and M of part 178 contain UN performance standards for 
non-bulk packagings adopted in PHMSA's ``HM-181'' final rules in 1990 
and 1991. 55 FR 52401 (December 21, 1990); 56 FR 66124 (December 20, 
1991). These performance standards criteria replaced the former 
detailed construction specifications and provide packaging design 
flexibility that is not possible with detailed design specifications. 
The performance criteria require design qualification testing and 
periodic retesting to verify whether a design type meets the 
performance standards. For combination packagings, drop and stacking 
testing are required, and the packaging must be ``capable'' of passing 
a vibration test. Sec. Sec.  178.603, 178.606, 178.608. The packaging 
(including the inner packagings) must be closed for testing, and tests 
must be carried out on the completed package that is prepared for 
testing, in the same manner as if prepared for transportation. Sec.  
178.602.
    In the HM-181 advance notice of proposed rulemaking (47 FR 16268 
(April 15, 1982)) and the notice of proposed rulemaking (52 FR 16482 
(May 5, 1987)), we proposed to require the hydrostatic pressure test in 
Sec.  178.605 to be performed on all inner packagings of UN standard 
combination packaging designs intended for transportation by aircraft. 
The pressure test would have addressed pressure differentials 
encountered during air transportation. This amendment was not adopted 
in the final rule. 55 FR 52402 (December 21, 1990). Instead, consistent 
with the ICAO Technical Instructions and the HMR in effect at the time, 
we elected to continue the requirement for all packagings containing 
liquids offered or intended for transportation aboard aircraft to be 
capable of withstanding without leakage a specified pressure 
differential. Sec.  173.27(c).
    Since that time, ICAO has added a note to Part 4; 1.1.6 of the 
Technical Instructions stating that the capability of a packaging to 
meet the pressure differential performance standard should be 
determined by testing, with the appropriate test method selected based 
on packaging type. However, ICAO has not adopted specific test methods 
in the Technical Instructions.
    Because the HMR do not specify test methods for verifying that a 
packaging meets the pressure differential requirement, some shippers 
and packaging manufacturers have used historical data (i.e., lack of 
incidents) and other methods (e.g. computer modeling, analogies, or 
engineering studies) to demonstrate that their packagings satisfy the 
pressure differential capability requirement. Shippers and packaging 
manufacturers have differing views on how the requirements are to be 
verified, and use various test methods to demonstrate compliance. This 
leads to a non-uniform approach, and it is difficult for PHMSA and FAA 
to verify whether a package meets the pressure differential requirement 
because no test report, documentation, or other proof of compliance is 
required by the HMR. Additionally, it does not provide an effective 
method of oversight to determine whether regulatory requirements are 
meeting actual forces encountered in transportation. If there is no 
control, the evaluation of quality and failure analysis is not 
possible. Even the most conscientious and safety-focused shippers have 
difficulty understanding how to comply with the requirements in Sec.  
173.27. Other shippers and packaging manufacturers may be taking 
advantage of the absence of specific requirements for verifying 
compliance.
    The absence of specific test methods in the HMR leads to 
inconsistencies in package integrity and results in varying levels of 
compliance among shippers. References to the pressure differential 
requirements in Sec.  173.27(c) are found throughout the regulations 
for packagings and packages offered for air transportation and 
transported by

[[Page 27275]]

aircraft without methods specified to verify compliance with this 
critical safety requirement. This results in wide disparities in 
packaging quality and the potential for sub-standard packages to be 
introduced into the air transport environment, increasing the 
probability of releases of hazardous materials aboard aircraft. In 
addition, some shippers or manufacturers may not realize that inner 
packagings of non-UN standard combination packagings are required to 
meet the pressure differential capability requirements of the HMR and 
the ICAO Technical Instructions. This includes packagings authorized 
under the limited quantity, consumer commodity, and Category B 
Biological Substance exceptions. A significant percentage of aircraft 
incidents involving liquid hazardous materials appear to result from 
failures of these packagings. We strongly believe the introduction of 
specific test methods and amendments that clarify the requirements for 
packagings offered for transportation by aircraft will enhance safety 
by reducing risk and level the playing field for shippers, 
manufacturers and air carriers alike.

II. Problem

    When a package reaches high altitudes during transport, it 
experiences low pressure on its exterior. This results in a pressure 
differential between the interior and exterior of the package since the 
pressure inside remains at the higher ground-level pressure. Higher 
altitudes create lower external pressures and, therefore, larger 
pressure differentials. This condition is especially problematic for 
combination packagings containing liquids. When an inner packaging, 
such as a glass bottle or plastic receptacle, is initially filled and 
sealed, the cap must be tightened to a certain torque to obtain sealing 
forces sufficient to contain the liquids in the packaging. This will 
require certain forces to be placed upon the bottle and cap threads as 
well as the sealing surface of the cap or cap liner to ensure the 
packaging remains sealed. Once at altitude, due to the internal 
pressure of the liquid acting upon the closure combined with the 
reduced external air pressure, the forces acting on the threads and the 
forces acting on the sealing surfaces will not be the same as when the 
packaging was initially closed. Under normal conditions encountered in 
air transport (26 kPa reduction in pressure at 8000 ft), the pressure 
differentials are not overly severe. However, if the compartment is 
depressurized at altitude or if the compartment is not pressurized at 
all, such as on certain ``feeder'' aircraft, the pressure differential 
may be severe enough to cause package failure and release of the 
hazardous materials in the aircraft. High-altitude stresses are 
encountered when cargo and feeder aircraft transport packages in non-
pressurized or partially-pressurized cargo holds.
    A seemingly ``minor'' incident can quickly escalate and result in 
irreversible, possibly catastrophic, consequences. For example, a 
closure failure of an inner container could cause an outer package to 
fail, resulting in fumes, smoke or flammable liquid acting as a 
catalyst to a more serious incident. The interaction of events 
occurring on aircraft, such as electrical fires, static electricity or 
other materials interacting with the leaking material, could result in 
a catastrophic event. The successful testing of inner packaging designs 
may lower the likelihood of such an event. Taking a systems-safety 
approach that includes multiple safety processes and redundancies can 
prevent a minor incident from becoming potentially much worse.
    PHMSA, FAA and, more recently, several international competent 
authorities all agree that the testing of design samples or prototypes 
of inner packagings or receptacles for pressure differential capability 
is key to preventing package failure in air transport. Testing also 
forms the basis of current performance standards in both the HMR and 
international regulations. Additionally, incident data and compliance 
verification testing of combination packagings intended for air 
transport and readily available in the marketplace indicate that an 
unacceptable number of packagings are not able to withstand pressure 
differential conditions normally incident to air transportation. Again, 
the packagings of particular concern are packagings that must be 
``capable'' of meeting pressure differential requirements, but are not 
required to be certified as meeting a specific performance test method 
to verify compliance with pressure differential performance standards. 
Incident data continue to show that packagings are leaking aboard 
aircraft; this likely is in part attributable to the fact that the HMR 
do not specifically provide test methods for determining that 
packagings meet the minimum pressure differential performance necessary 
to withstand conditions of air transport. It cannot be overemphasized 
that any incident, such as a package failure, involving hazardous 
materials in air transportation is unacceptable.
    Four recent studies simulated the impact of high-altitude on 
package integrity. These conditions result in extreme changes in 
pressure when compared to packages being transported at or close to sea 
level. These four studies were discussed in detail in the ANPRM 
published under this docket [73 FR 38361; July 7, 2008] and are 
available for review at https://www.regulations.gov.
    In the first study, FAA analyzed incident data from the DOT 
Hazardous Materials Information System (HMIS) for the years 1998 and 
1999 and focused on properly declared hazardous material shipments. The 
study concluded that of 1,583 air incidents reported to PHMSA, a 
failure of inner packagings in combination packaging designs 
contributed to 333 spills or leaks. In the second study, United Parcel 
Service (UPS) presented its findings to the American Society of Testing 
and Materials (ASTM) outlining the conditions that packages experience 
in the air transport environment. In 2002, the FAA initiated a study 
with Michigan State University (MSU) to replicate actual air and pre- 
and post-truck transportation conditions to determine which conditions 
contribute to package failures. In this third study on conditions 
experienced in air transportation, FAA examined the effects of 
vibration alone, altitude alone, and a combination of vibration and 
altitude on the performance of UN standard hazardous material 
combination packages containing liquids. In 2003, PHMSA also initiated 
a study with MSU to compare the HMR requirements and the testing used 
in the FAA/MSU study to provide for a more thorough evaluation of the 
performance of liquid hazardous materials in combination packagings 
when subjected to the conditions of air transport. This fourth round of 
testing was conducted on a smaller number of packaging designs; 
however, a much greater number of packagings of each design were tested 
in the study.
    During the first half of 2007, PHMSA conducted a comprehensive 
assessment of hazardous materials transportation incidents occurring in 
air transportation from 1997 through 2006. This study and its 
corresponding data may be accessed in the public docket for this 
rulemaking. The study concluded that there has been no appreciable 
reduction in package failures over the past 10 years. It is estimated 
that 191,429 tons of liquid hazardous materials contained in 
approximately 16.9 million combination packages are transported by 
aircraft annually. Of that total, the analysis concluded that 
approximately 483 combination packagings containing liquids fail in air 
transportation each

[[Page 27276]]

year with an average of two incidents reported as ``serious.'' \2\ 
However, any incident, such as a package failure, involving hazardous 
materials in air transportation is unacceptable.
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    \2\ The HMR define a ``serious incident'' as one that involves 
one or more of the following: (1) A fatality or major injury caused 
by the release of a hazardous material; (2) the evacuation of 25 or 
more persons as a result of release of a hazardous material or 
exposure to fire; (3) a release or exposure to fire which results in 
the closure of a major transportation artery; (4) the alteration of 
an aircraft flight plan or operation; (5) the release of radioactive 
materials from Type B packaging; (6) the release of over 45 liters 
(11.9 gallons) or 40 kilograms (88.2 pounds) of a severe marine 
pollutant; or (7) the release of a bulk quantity (over 450 liters 
(119 gallons) or 400 kilograms (882 pounds)) of a hazardous 
material. Sec.  171.15.
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    The 2007 study concluded that of the approximately 483 air 
incidents reported each year, at least 44 percent involved the failure 
of inner packaging closures within a combination outer packaging as the 
primary cause. Such failures could have been the result of pressure 
differential (packages closed at sea level subjected to lower pressure 
on planes), stress relaxation of the closure (closures that appear 
tight but loosen during transportation), improper closures, vibration, 
or some other cause. The analysis also suggested that most incidents 
involved combination packagings containing flammable liquids (e.g., 
paint and paint related material) of varying degrees of hazard. Some 
additional statistical data from the 2007 incident review include:
     Over 40% of failures of combination packages containing 
liquids in air transportation involve closures and/or inner 
receptacles.
     Flammable liquids are the most common liquid hazardous 
materials released from failed packages in air transportation. If such 
materials found an ignition source, it could result in a fire or 
explosion.
     In incident years 2005-2006, 18 of 953 incidents involving 
combination packagings containing liquids, or 2%, occurred on 
passenger-carrying aircraft. Although low when compared to incidents 
occurring on cargo-carrying aircraft, this percentage of package 
failures continues to be a troubling statistic.
     Combination packages containing liquids that fail in air 
transportation release an average 2 liters (0.5 gallons) of liquid 
hazardous materials.

III. ANPRM

    On July 7, 2008, PHMSA published an advance notice of rulemaking 
(ANPRM; 73 FR 38361) seeking to identify cost-effective solutions to 
reduce incident rates and the potential severity of incident 
consequences without placing unnecessary burdens on the regulated 
community. We solicited comments on how to accomplish these goals, 
including measures to: (1) Enhance the effectiveness of performance 
testing for packagings used to transport hazardous materials on 
aircraft; (2) more clearly indicate the responsibilities of shippers 
that offer packages for air transport in the HMR; and (3) authorize 
alternatives for enhancing package integrity. We asked a series of 
questions related to the packaging of liquid hazardous materials in 
combination packagings that are offered for transportation and 
transported by aircraft. A total of 13 persons submitted comments in 
response to the ANPRM; the list of commenters includes:

AHS Association of Hazmat Shippers, Inc.
Ecolab Ecolab, Inc.
ALPA Air Line Pilots Association, International
COSTHA The Council on Safe Transportation of Hazardous Articles, 
Inc.
IOPP Institute of Packaging Professionals
CPC Chemical Packaging Committee
FedEx Federal Express
ISTA International Safe Transit Association
ASTM ASTM International
ICC ICC The Compliance Center, Inc.
MSU Michigan State University School of Packaging
Viking Viking Packing Specialist
DGAC Dangerous Goods Advisory Council

    Commenters generally agree that regulatory changes are necessary to 
address safety issues related to the transportation of hazardous 
materials in non-UN standard packagings on board aircraft. However, 
commenters had varying views on the scope of the safety problem or 
specific regulatory amendments necessary to eliminate or reduce 
problems should they exist. Some commenters also questioned the 
validity of studies conducted and analysis of the underlying data used 
that motivated PHMSA to initiate rulemaking action. These comments are 
summarized below.

A. Studies and Data

    As indicated previously, recent studies have simulated the impact 
of high altitudes on packaging integrity. These studies suggest that 
the current testing requirements (or lack thereof) under the HMR may 
not adequately address the conditions encountered during air 
transportation. Moreover, a review of incident data conducted by FAA 
and PHMSA supports the conclusion that some combination packaging 
designs used to transport hazardous materials by aircraft may not meet 
the capability standards mandated under the HMR. Indeed, the testing 
conducted suggests that the capability standards themselves may not be 
sufficiently rigorous to ensure that packagings maintain their 
integrity under conditions normally incident to air transportation. 
Study data, incidents, and several years of feedback from industry 
indicate that, without specific standards and protocols, a consistent 
approach to compliance cannot be achieved. This can lead to a 
potentially unsafe condition.
    Some commenters cited concerns over how two of the studies were 
conducted or suggested that the problems discussed in the ANPRM may not 
be as serious as presented. For example, Ecolab identifies what it 
contends are at least three discrepancies in the two air packaging 
integrity studies conducted by MSU in 2002 and 2003 on behalf of PHMSA 
and FAA. Ecolab contends that these discrepancies, identified by CPC 
and published in a 2006 Hazmat Packager and Shipper article, occurred 
because some of the tests utilized for the studies were not conducted 
in accordance with the HMR or corresponding international standards. 
One study allegedly used an improper closure design that differed from 
the originally tested design. CPC asserted that the improper closure 
design used in the study raised the number of packaging failures from 
14 to 42, an increase of 75%. In its comments, Ecolab contends that a 
successfully tested package will not leak when closed properly and 
subjected to normal conditions of air transport. As a result of 
conclusions drawn from these initial studies and to address challenges 
made to the assumptions used in their methodology, further studies were 
budgeted and carried out. PHMSA and FAA acknowledge that some of the 
studies utilized packagings that did not conform in all respects with 
HMR requirements. The characteristics of the packagings tested were 
fully disclosed in the study reports. We do not agree that the minor 
differences in the closures used affects the conclusions of the 
studies. We note that the studies were not used to determine compliance 
with HMR requirements, but rather to measure the capability of 
commercially available packaging designs to withstand the unique 
conditions encountered in air transportation.
    Although most commenters support the actual testing of inner 
packaging designs for pressure differential capabilities, several 
commenters doubt that incidents are occurring in air transport as a 
result of the lack of actual testing. AHS notes that incident reports 
submitted to PHMSA in accordance with reporting requirements in Sec.  
171.16 of the HMR do not indicate whether an inner packaging failed 
because it had

[[Page 27277]]

not been tested or because it was not capable of withstanding forces 
encountered in transportation. We note that it is highly unlikely that 
a carrier or other entity without intimate knowledge of a packaging's 
design or overall integrity would be able to report, as a root cause, 
that an incident that occurred in air transportation resulted from a 
lack of actual testing or the packaging's inability to withstand the 
forces inherent to transportation by aircraft. However, by carefully 
analyzing available incident data and conducting controlled laboratory 
studies of commercially available packaging designs, we can conclude 
that the actual testing for pressure differential capability was either 
conducted incorrectly or not conducted at all.
    COSTHA contends that PHMSA should not be alarmed if leakage from an 
inner packaging is contained within its outer packaging and suggests 
that seepage from a closure over time should be evaluated differently 
than a complete failure where the entire contents of an inner packaging 
are released within an outer packaging. We disagree. A successfully 
tested and properly filled and closed inner packaging design should not 
leak under normal conditions encountered in air transportation. 
Additionally, an inferior inner packaging design or component would be 
identified through the pass/fail criteria when originally tested. 
Because the primary receptacle within a combination packaging system is 
the most important component of that system in air transport, it should 
not fail except under extreme or highly abnormal conditions.
    Regarding the distribution hazards experienced in today's air 
transport environment, Ecolab asserts that shipments have always been 
subjected to multiple flight segments and any consequences resulting 
from that environment. Ecolab is correct; however, although shipments 
have routinely utilized multiple flight segments in the past, the 
proliferation of sort systems and feeder aircraft systems has changed 
the environment shipments normally encountered during transit. Today, 
air carriers use multiple mechanical handling systems to sort packages, 
and the number of distribution points has grown with the natural 
expansion of commerce.
    In its comments, Ecolab states that better enforcement of existing 
regulations related to packaging integrity is key to reducing the 
number of incidents in air transportation. We agree. Once verifiable 
and repeatable testing standards are adopted in the HMR, shippers, 
packaging test labs, and government regulators can all measure 
packaging integrity using the same process, procedures, and protocols. 
Consistency is the most efficient and effective way to measure success 
or failure. Ecolab also notes that, according to PHMSA's HMIS incident 
database, human error is cited as an accident cause six times more 
frequently than packaging failure. An example of human error could be 
the deliberate or inadvertent consequences resulting from failure to 
follow a packaging manufacturer's customer notification or closure 
instructions. An example of packaging failure would be differences in 
manufacturing tolerances that result in leakage (failure) from an 
otherwise properly closed inner packaging design. Again, this supports 
the multi-layered safety system concept.

B. Pressure Differential Testing

    In the ANPRM, we noted that because specific test methods are not 
included in the HMR or the ICAO Technical Instructions, there are 
inconsistencies in package integrity and varying levels of compliance 
among shippers. For example, because the pressure differential and 
vibration capability standards for combination packagings are not 
required to be verified by test protocols, some shippers (self-
certifiers) or manufacturers have used historical shipping data, 
computer modeling, analogies to tested packagings, engineering studies, 
or similar methods to determine that their packagings meet pressure 
differential and vibration capability standards.
    Shippers, carriers, packaging manufacturers, and testing facilities 
generally agree that the current capability requirements for air 
packagings are difficult to comply with and suggest that specific test 
methods designed to demonstrate that packagings will withstand 
conditions encountered during air transportation should be specified in 
the HMR. Ecolab states that the current regulatory language in the HMR 
regarding the pressure differential capability of inner packagings 
should be replaced with recognized industry standards for testing and 
no additional testing should be proposed. ALPA recommends that the HMR 
incorporate the language contained in the ICAO Technical Instructions 
clarifying test methods and responsible parties. For example, the ICAO 
Technical Instructions suggest test methods appropriate for certain 
types of inner packagings and liquid hazardous materials in order to 
promote compliance with the prescribed performance standard. ALPA 
contends the lack of standardized, easily understandable testing 
protocol contributes to incidents in air transportation. Ecolab and 
Viking both agree that, to properly determine the capability of a 
packaging design, it must first be tested. ISTA asserts that the 
simultaneous combination of low pressure and vibration exerted on a 
package is the only way to accurately replicate conditions encountered 
by a package in air transportation.
    The HMR and ICAO Technical Instructions both require that a shipper 
consider the pressure differential capability for an inner packaging 
intended to contain a mixture or solution based on its vapor pressure. 
Many commenters agree that determining the vapor pressure of a mixture 
or solution is problematic, costly, and does not materially contribute 
to reducing the likelihood of packaging failure. Ecolab believes that a 
95 kPa differential capability is a realistic and attainable indication 
of inner packaging integrity and that the 75 kPa capability for some 
hazard classes and packing groups should be eliminated for clarity and 
increased safety. In addition, Ecolab states that PHMSA should codify 
any testing protocol adopted in Subpart M of Part 178. Because the 
proposed amendments in this notice apply to non-UN standard packagings 
as well as UN standard packagings, and the Part 178 requirements apply 
to UN standard packagings only, it is appropriate that the amendments 
proposed in this notice be codified in Sec.  173.27. We appreciate and 
understand commenter frustration with regard to calculating the vapor 
pressure of a mixture or solution to determine the appropriate 
packaging capable of withstanding the prescribed pressure differential. 
In this NPRM, we are proposing an alternative method that can be used 
to calculate the appropriate packaging required for a mixture or 
solution without testing to determine vapor pressure.

C. Alternatives to Testing

    The HMR and ICAO Technical Instructions both allow a liquid 
hazardous material to be contained in an inner packaging that does not 
itself meet the pressure differential performance standard, provided 
that the inner packaging is packed within a supplementary packaging 
that does meet the pressure requirements. In their comments, AHS and 
ICC ask PHMSA to retain in the HMR the option for a shipper to use 
supplementary packaging that meets the pressure differential 
requirements. PHMSA agrees with commenters on this issue and is not

[[Page 27278]]

proposing to amend the HMR to do otherwise.
    The HMR currently permit the use of variations in inner packagings 
of a tested combination package, without further testing of the 
package, provided an equivalent level of performance is maintained 
under conditions prescribed in Sec.  178.601. ICC states that a 
packaging designed to successfully withstand the Sec.  178.601(g)(2) 
Variation 2 test protocols should not be required to contain inner 
packagings capable of meeting the pressure differential and vibration 
capabilities of the HMR. We disagree. A primary inner packaging or 
receptacle of known or questionable inferiority is unacceptable in air 
transportation regardless of whether the outer packaging is of a higher 
integrity. No other commenters opposed actual testing of inner 
packagings of combination packagings intended to contain liquids for 
transportation by aircraft.
    ICAO recently adopted revised packaging instructions for 
incorporation in the ICAO Technical Instructions that will become 
effective January 1, 2011. The new packing instructions require a 
secondary means of closure for all liquids in combination packagings. 
This requirement may be satisfied by using a liner or other form of 
containment when the secondary means of closure cannot be applied. 
Inner packagings containing liquids of Packing Group I must be placed 
in rigid leakproof receptacles with absorbent material before placing 
them in outer packagings of a combination package. None of the comments 
submitted to the ANPRM oppose this requirement; those who did comment 
on this requirement support its adoption in the HMR.

D. Packaging Components

    Many commenters state that pressure differential and vibration 
capability standards should apply to both specification and non-
specification packaging designs. Ecolab asserts that a properly tested 
and closed inner packaging design offers no risk in air transport. In 
evaluating the inherent risks assumed in air transportation and the 
potential for high consequence events should an incident occur, ALPA 
supports multiple layers of redundancy to include actual testing of 
inner packaging designs and the use of liners, absorbent material, and 
secondary means of closure. Commenters agree that the interaction 
between an inner packaging containing a liquid and its closure are 
critical in air transport. COSTHA believes that if any component of a 
tested design is changed, and it is not an exact replacement, quality 
review and testing is required. Viking believes that a successfully 
tested inner packaging is only one (albeit a major one) part of a 
closure system that also uses a protective liner and is properly 
oriented when stored or transported. PHMSA and FAA both agree that the 
verification of packaging integrity through testing and the additional 
redundant amendments proposed in this notice will ensure consistency in 
the quality of packagings used for the air transport of liquid 
hazardous materials and mitigate or eliminate the consequences of an 
incident or accident should one occur.

IV. Summary of Proposals in This NPRM

    Because aircraft accidents caused by leaking or breached hazardous 
materials packages can have significant or catastrophic consequences, 
the air transportation of hazardous materials requires clear standards, 
exceptional diligence, and attention to detail. To address the 
regulatory deficiencies previously described in detail, we are 
proposing amendments to the HMR to strengthen the integrity of packages 
intended for transport by aircraft.
    Most commenters support adoption of the ICAO Technical Instructions 
requirement for a secondary means of closure and utilization of a liner 
if such secondary means of closure is infeasible or impracticable. 
Further, most commenters agree that the most effective means to ensure 
that combination packagings are capable of meeting specified 
performance standards is actual testing. We agree. Therefore, in this 
NPRM we are proposing to adopt the new ICAO Technical Instructions 
requirements for combination packagings and test protocols that may be 
used to demonstrate that such packagings conform to applicable 
performance standards. If adopted, these amendments will add clarity to 
the processes required in determining whether a packaging design is 
capable of meeting the forces encountered in air transportation. We are 
confident that these enhancements to current regulatory requirements 
will result in a higher level of safety in air transportation by 
reducing the likelihood of combination package failures in air 
transportation.
    The following is a summary of the proposals in this NPRM.

A. Incorporation of Revised ICAO Technical Instructions Packaging 
Provisions

    Currently under the HMR, stoppers, corks, or other such friction-
type closures must be held securely, tightly, and effectively in place 
by positive means. See Sec.  173.27(d). However, a screw-type closure 
on any packaging must only be secured to prevent the closure from 
loosening due to ``vibration or substantial change in temperature.'' We 
have stated in letters of clarification that a secured closure should 
incorporate a secondary means of maintaining a seal, such as a shrink-
wrap band or heat sealed liner. (We have included three of those 
letters (02-0302 dtd. January 23, 2003; 04-0011 dtd. May 12, 2004; 07-
0174 dtd. March 17, 2008) in the docket for information and guidance.) 
Additionally, laboratory studies conducted on behalf of PHMSA and FAA 
concluded that a simple application of tape on a screw-type closure 
prevented ``back-off'' under even extreme conditions. We also note for 
the purposes of this notice that:
     Liners typically must be manually inserted into a 
packaging before filling. Because most packaging systems can be 
automated or are already automated with some form of secondary closure 
being applied, costs and regulatory burden to shippers should be 
minimal.
     Most Packing Group I liquids already require a leakproof 
liner in the HMR and ICAO Technical Instructions.
     A liner or secondary means of positive closure should not 
affect an existing UN standard packaging design as in most cases it 
will not be considered a new design.
     Requiring a secondary positive means of closure combined 
with required verification of pressure differential capability adds a 
layered systems-approach to air transportation safety.
    Packaging failures in air transportation often are the result of 
closures that have loosened in transportation. Such leaks are 
potentially dangerous in all modes of transportation, but have the 
potential for catastrophic results in air transportation. Therefore, we 
are proposing to revise Sec.  173.27(d) to clearly state that all 
friction and screw type closures must be secured by a secondary means 
of positive closure. We believe that adoption of this requirement 
provides a necessary added level of protection to prevent packages from 
leaking in air transportation. For liquids assigned to Packing Groups 
II or III, a leakproof liner may be used to satisfy the secondary 
closure requirement where it cannot be applied or it is impracticable 
to apply. For liquids of Packing Group I, we are proposing to revise 
Sec.  173.27(e) to require secondary means of closure, absorbent 
material, and a rigid, leakproof liner or

[[Page 27279]]

intermediate packaging. Also, for clarity we are proposing to remove 
the reference to Division 5.2 materials from the Sec.  173.27(e) 
introductory text.

B. Enhanced Pressure Differential Capability Standard

    Currently, the HMR require all packagings containing liquid 
hazardous materials intended for transportation by aircraft to be 
capable of withstanding, without leakage, an internal gauge pressure of 
at least 75 kPa for liquids in Packing Group III of Class 3 or Division 
6.1 or 95 kPa for all other liquids, or a pressure related to the vapor 
pressure of the liquid to be conveyed, whichever is greater. See Sec.  
173.27(c). This requirement also applies to liquids excepted from 
specification packaging, such as limited quantities and consumer 
commodities. Liquids contained in inner receptacles that do not meet 
the minimum pressure requirements in Sec.  173.27(c) may be placed into 
receptacles that do meet the pressure requirements to ensure that the 
completed packaging--inner receptacles plus outer packaging--will 
withstand pressures typically encountered in air transportation. Single 
and composite packagings, or any packaging subject to hydrostatic 
pressure testing under Sec.  178.605, must have a marked test pressure 
of not less than 250 kPa for liquids in Packing Group I, 80 kPa for 
liquids in Packing Group III of Class 3 or Division 6.1, and 100 kPa 
for other liquids.
    As discussed in detail earlier in this preamble and in the ANPRM, 
testing conducted on behalf of FAA and PHMSA indicates that many 
combination packagings fail when subjected to conditions intended to 
simulate the pressures encountered in the air transportation 
environment. One possible conclusion is that these packagings might not 
be capable of meeting the pressure differential capability standards. 
Without testing there is no assurance that these packagings are capable 
of meeting the prescribed standards. For air transportation, such 
deficiencies in packaging integrity are unacceptable.
    In this notice, we are proposing that conformance with the pressure 
differential requirements for rigid packagings may be demonstrated by 
testing performed in accordance with ASTM D6653, ``Standard Test 
Methods for Determining the Effects of High Altitude on Packaging 
Systems by Vacuum Method'' or ASTM D4991, ``Standard Test Method for 
Leakage Testing of Empty Rigid Containers by Vacuum''.
    For flexible packaging, we are proposing that conformance with the 
pressure requirements may be demonstrated by pressure differential 
testing performed in accordance with ASTM F 1140, ``Standard Test 
Methods for Internal Pressurization Failure Resistance of Unrestrained 
Packages for Medical Applications'', ASTM D 3078, ``Standard Test 
Method for Determination of Leaks in Flexible Packaging by Bubble 
Emission'' or a generic test method outlined in a proposed new Appendix 
E to Part 173.
    Additional test methods that may be used to confirm pressure 
differential capability are the hydrostatic pressure test in Sec.  
178.605 and the International Safe Transit Association's ``ISTA 3A, 
Packaged-Products for Parcel Delivery System Shipment 70 kg (150 lb) or 
Less.'' However, the ISTA 3A test method is considered more costly and 
complex due to the high cost of equipment and specialized operators 
needed to conduct it.
    We have recently had the privilege of working with the German 
Federal Institute for Materials Research and Testing (BAM) on the 
problematic issue of calculating vapor pressures for liquids at the 
transportation reference temperatures (50-55 [deg]C) as well as for 
mixtures and solutions. The proposed table in Appendix E of this notice 
provides guidance on determining these values based on the relationship 
between boiling points and vapor pressures. It allows the shipper or 
product manufacturer to estimate the required capability (test 
pressure) of their packaging based on the individual constituent in a 
mixture or solution with either the lowest boiling point or the highest 
vapor pressure at 50 [deg]C. We invite comments on this potentially 
very positive initiative.

C. Combined Enhanced Pressure Differential Capability Standard and 
Incorporation of Revised ICAO Technical Instructions Packaging 
Provisions

    Laboratory studies have shown that testing inner packagings or 
receptacles of commercially available combination packaging designs 
intended or marketed as authorized for transportation by aircraft 
achieves an approximate effectiveness rating of 95 percent, with the 
current compliance rate among shippers unknown. The current compliance 
rate for the use of liners or secondary means of positive closure by 
shippers is estimated to be at least 70 to 90 percent, with an 
effectiveness rate of 95 to 100 percent. Consequently, we have decided 
to propose in this notice a combination of both regulatory alternatives 
to achieve our objective of a cost-effective systems approach to safety 
that provides redundancy where necessary and promotes compliance by 
issuing regulations that are clear and easier to understand.

D. Vibration Testing

    Section 173.27(c) of the HMR prescribes a pressure differential 
capability standard for inner packagings of combination packagings 
intended for air transport. In addition, in accordance with Sec.  
178.608, combination packagings must be capable of passing a prescribed 
vibration test. As discussed in detail elsewhere in this preamble, in 
order to substantially decrease the likelihood of a hazardous materials 
release in air transport, we are proposing to prescribe specific test 
protocols and standards for determining whether an inner package or 
receptacle is capable of meeting the pressure differential requirements 
specified in the regulations. However, we are not proposing to revise 
the current vibration capability standard. Testing to ascertain 
conformance with a pressure differential capability standard is 
significantly more cost effective than testing to ascertain conformance 
with a vibration capability standard. Vibration testing generally 
requires more expensive equipment and specially trained operators. 
Moreover, laboratory studies have concluded that the application of a 
secondary means of closure to a packaging capable of withstanding the 
pressure differentials encountered in air transport substantially 
reduces the overall failure rate of packages.
    It is our understanding that a number of shippers and packaging 
vendors currently use random vibration tests, such as those in the ISTA 
3A or ASTM D 4169 standards, in combination with pressure differential 
testing for packagings intended for air transport. While the HMR 
prescribe a specific vibration test protocol, it appears that the 
recognized random vibration test methods, combined with pressure 
differential testing, achieve the intent of the test protocols in the 
HMR--that is, to ensure that the packaging will withstand environmental 
conditions normally encountered in air transportation. In our opinion, 
the use of sequential or combined pressure differential and vibration 
testing in accordance with ISTA, ASTM, or other test protocols would 
exceed the current capability standards for pressure differential and 
vibration for packages intended for air transportation. We would 
consider that inner containers demonstrating conformance to these 
standards would not be required to

[[Page 27280]]

undergo further testing for pressure or vibration capability standards 
when placed in an outer packaging for packages intended for air 
transportation. As discussed in greater detail in Section III of this 
notice, for certain types of packagings, the HMR provide for separate 
testing of packaging components so that if one component conforms to 
the applicable performance standard, the secondary components need not 
meet those standards.

V. Rulemaking Analysis and Notices

A. Statutory/Legal Authority for This Rulemaking

    This NPRM is published under authority of Federal hazardous 
materials transportation law (Federal hazmat law; 49 U.S.C. 5101 et 
seq.). Section 5103(b) of Federal hazmat law authorizes the Secretary 
of Transportation to prescribe regulations for the safe transportation, 
including security, of hazardous materials in intrastate, interstate, 
and foreign commerce.

B. Executive Order 12866 and DOT Regulatory Policies and Procedures

    This proposed rule is a significant regulatory action under section 
3(f) Executive Order 12866 and, therefore, was reviewed by the Office 
of Management and Budget (OMB). The proposed rule is a significant rule 
under the Regulatory Policies and Procedures order issued by the U.S. 
Department of Transportation (44 FR 11034). We have completed a 
regulatory evaluation and placed it in the docket for this rulemaking.
    In this rulemaking, we considered three regulatory alternatives: 
(1) Require a secondary means of closure on inner packagings or a liner 
in all combination packaging designs containing liquids; (2) require 
testing to determine whether an inner packaging intended to contain 
liquids is capable of withstanding the reduced pressures of air 
transport; or (3) require a combination of both regulatory 
alternatives. We are proposing the combination alternative, number 3. 
Costs for the combination alternative range from $2.2M to $5.7M while 
net benefits range from $41.6M to $67.9M. at a 7% discount rate over a 
10-year period. Benefit-cost ratios for the combination alternative 
range from 7.3:1 to 31.5:1. We invite commenters to address the 
potential costs of the enhanced packaging requirements in this notice, 
including the number of inner and outer packaging designs that would be 
affected.

C. Executive Order 13132

    This notice has been analyzed in accordance with the principles and 
criteria contained in Executive Order 13132 (``Federalism''). This 
notice preempts State, local and Indian tribe requirements but does not 
propose any regulation with substantial direct effects on the States, 
the relationship between the national government and the States, or the 
distribution of power and responsibilities among the various levels of 
government. Therefore, the consultation and funding requirements of 
Executive Order 13132 do not apply.
    The Federal hazardous materials transportation law, 49 U.S.C. 5101-
5127, contains an express preemption provision (49 U.S.C. 5125(b)) 
preempting State, local and Indian tribe requirements on the following 
subjects:
    (1) The designation, description, and classification of hazardous 
materials;
    (2) The packing, repacking, handling, labeling, marking, and 
placarding of hazardous materials;
    (3) The preparation, execution, and use of shipping documents 
related to hazardous materials and requirements related to the number, 
contents, and placement of those documents;
    (4) The written notification, recording, and reporting of the 
unintentional release in transportation of hazardous material; or
    (5) The design, manufacture, fabrication, marking, maintenance, 
recondition, repair, or testing of a packaging or container 
represented, marked, certified, or sold as qualified for use in 
transporting hazardous material.
    This notice addresses covered subject item (5) described above and 
preempts State, local, and Indian tribe requirements not meeting the 
``substantively the same'' standard.
    Federal hazardous materials transportation law provides at 49 
U.S.C. 5125(b)(2) that, if DOT issues a regulation concerning any of 
the covered subjects, DOT must determine and publish in the Federal 
Register the effective date of Federal preemption. The effective date 
may not be earlier than the 90th day following the date of issuance of 
the notice and not later than two years after the date of issuance. The 
effective date of Federal preemption of this notice will be 90 days 
from publication in the Federal Register.

D. Executive Order 13175

    This notice has been analyzed in accordance with the principles and 
criteria contained in Executive Order 13175 (``Consultation and 
Coordination with Indian Tribal Governments''). Because this proposed 
rule does not have tribal implications and does not impose direct 
compliance costs, the funding and consultation requirements of 
Executive Order 13175 do not apply.

E. Regulatory Flexibility Act, Executive Order 13272, and DOT 
Procedures and Policies

    The Regulatory Flexibility Act (5 U.S.C. 601-611) requires each 
agency to analyze proposed regulations and assess their impact on small 
businesses and other small entities to determine whether the proposed 
rule is expected to have a significant impact on a substantial number 
of small entities. A regulatory evaluation for this NPRM, which 
includes a detailed small business impact analysis, is in the public 
docket for this rulemaking. Based on the analysis in the public docket, 
I certify that while this notice will impact a significant number of 
small entities, it will not have a significant economic impact on a 
substantial number of small entities.
    This notice has been developed in accordance with Executive Order 
13272 (``Proper Consideration of Small Entities in Agency Rulemaking'') 
and DOT's procedures and policies to promote compliance with the 
Regulatory Flexibility Act to ensure potential impacts of draft rules 
on small entities are properly considered.

F. Unfunded Mandates Reform Act of 1995

    This notice does not impose unfunded mandates under the Unfunded 
Mandates Reform Act of 1995. It will not result in costs of $141.3 
million or more, in the aggregate, to any of the following: State, 
local, or Native American tribal governments, or the private sector.

G. Paperwork Reduction Act

    PHMSA currently has an approved information collection under Office 
of Management and Budget (OMB) Control Number 2137-0572, ``Testing 
Requirements for Non-Bulk Packaging,'' with an expiration date of March 
31, 2010. This NPRM may result in an increase in the annual burden and 
costs of this information collection due to proposed changes to require 
packaging manufacturers to conduct testing to confirm that a 
combination packaging intended for the air transportation of liquid 
hazardous materials is capable of withstanding the pressures 
encountered on board aircraft and to maintain a documented record of 
the test results.
    Under the Paperwork Reduction Act of 1995, no person is required to 
respond to an information collection

[[Page 27281]]

unless it has been approved by OMB and displays a valid OMB control 
number. Section 1320.8(d), title 5, Code of Federal Regulations 
requires that PHMSA provide interested members of the public and 
affected agencies an opportunity to comment on information and 
recordkeeping requests.
    This notice identifies a revised information collection request 
that PHMSA will submit to OMB for approval based on the requirements in 
this proposed rule. PHMSA has developed burden estimates to reflect 
changes in this proposed rule, and estimates the information collection 
and recordkeeping burden as proposed in this rule to be as follows:
    OMB Control No.: 2137-0572.
    Annual Number of Respondents: 1,496.
    Annual Number of Responses: 29,712.
    Annual Burden Hours: 54,525.
    Annual Burden Costs: $1,557,779.25.
    PHMSA specifically requests comments on the information collection 
and recordkeeping burdens associated with developing, implementing, and 
maintaining these requirements for approval under this proposed rule.
    Requests for a copy of this information collection should be 
directed to Deborah Boothe or T. Glenn Foster, Office of Hazardous 
Materials Standards (PHH-11), Pipeline and Hazardous Materials Safety 
Administration, 1200 New Jersey Avenue, SE., Washington, DC 20590-0001, 
Telephone (202) 366-8553.
    Address written comments to the Dockets Unit as identified in the 
ADDRESSES section of this rulemaking. We must receive comments 
regarding information collection burdens prior to the close of the 
comment period identified in the DATES section of this rulemaking. In 
addition, you may submit comments specifically related to the 
information collection burden to the PHMSA Desk Officer, Office of 
Management and Budget, at fax number 202-395-6974. If these proposed 
requirements are adopted in a final rule, PHMSA will submit the revised 
information collection and recordkeeping requirements to OMB for 
approval.

H. Environmental Assessment

    The National Environmental Policy Act (NEPA), Sec. Sec.  4321-4375, 
requires Federal Agencies to analyze regulatory actions to determine 
whether the action will have a significant impact on the human 
environment. The Council on Environmental Quality (CEQ) regulations 
order Federal Agencies to conduct an environmental review considering 
(1) the need for the action, (2) alternatives to the action, (3) 
environmental impacts of the action and alternatives, and (4) the 
agencies and persons consulted during the consideration process. 40 CFR 
1508.9(b).
    Purpose and Need. As discussed elsewhere in this preamble, PHMSA 
proposes to amend requirements in the Hazardous Materials Regulations 
to enhance the integrity of inner packagings or receptacles of 
combination packagings containing liquid hazardous material by ensuring 
they remain intact when subjected to the reduced pressure and other 
forces encountered in air transportation. In order to substantially 
decrease the likelihood of an unintentional hazardous materials release 
to the environment, the proposed amendments in this notice prescribe 
specific test protocols and standards for determining whether an inner 
packaging or receptacle is capable of meeting the pressure differential 
requirements specified in the regulations and aligns the HMR with 
international air transportation standards.
    Alternatives. PHMSA considered four possible alternatives to 
strengthen packaging requirements for air shipments of liquid hazardous 
materials:
    Alternative 1: Do nothing. Under this alternative, the current 
regulatory scheme applicable to air shipment of hazardous liquids would 
continue in place. We rejected this alternative because newly 
identified safety risks would not be addressed.
    Alternative 2: Require that friction and screw type closures of 
inner packagings intended to contain liquids as part of a combination 
packaging to be secured by a secondary means of closure. Under this 
alternative, we would adopt the packaging amendments included in the 
2011-2012 edition of the ICAO Technical Instructions. Specifically, we 
would require friction and screw type closures of inner packagings 
intended to contain liquids as part of a combination packaging to be 
secured by a secondary means of closure. For liquids assigned to 
Packing Groups II or III, a leakproof liner could be used to satisfy 
the secondary closure requirement where it could not be applied or 
would be impracticable to apply. For liquids of Packing Group I, a 
secondary means of closure, absorbent material and a leakproof liner 
would be required. We rejected Alternative 2. While it would address 
many of the safety issues associated with the transportation of liquid 
hazardous materials, Alternative 2 alone does not represent a 
comprehensive systems-oriented regulatory solution and would not 
address problems associated with the current pressure differential 
capability standard.
    Alternative 3: Require enhanced pressure differential capability 
requirements on all inner packagings intended to contain liquids as 
part of a combination packaging. Currently, the HMR require that all 
packages transported by air and for which retention of liquids is a 
basic function must be capable of withstanding, without leakage, a 
certain pressure differential, which is usually 95 kilopascals (kPa) 
(Sec.  173.27[c]). This integrity standard applies to both 
specification and non-specification packaging. Under this alternative, 
we would require packaging manufacturers to conduct testing to confirm 
that a combination packaging intended for the air transportation of 
liquid hazardous materials is capable of withstanding the pressures 
encountered on board aircraft and to maintain a documented record of 
the test results. We rejected this alternative. While it would address 
many of the safety issues associated with the transportation of liquid 
hazardous materials, Alternative 3 alone does not represent a 
comprehensive systems-oriented regulatory solution. Moreover, it does 
not address critical international harmonization issues.
    Alternative 4: Adopt the provisions in both Alternatives 2 and 3. 
Under this alternative, PHMSA would adopt the new and revised 
regulatory provisions summarized in the discussion of Alternatives 2 
and 3 above. This is the selected alternative. The proposed testing 
requirements will enhance safety by ensuring that all liquid hazardous 
materials shipments are contained in packages capable of withstanding 
normal conditions encountered in air transport and packaged to reduce 
the possibility of damage that could lead to an incident. It also 
harmonizes domestic packaging requirements with international 
standards, thereby reducing confusion, promoting safety, and 
facilitating efficient transportation.
    Analysis of Environmental Impacts. Hazardous materials are 
substances that may pose a threat to public safety or the environment 
during transportation because of their physical, chemical, or nuclear 
properties. The hazardous material regulatory system is a risk 
management system that is prevention-oriented and focused on 
identifying a safety hazard and reducing the probability and quantity 
of a hazardous material release. Releases of hazardous materials can 
result in explosions or fires, while radioactive, toxic, infectious, or 
corrosive hazardous

[[Page 27282]]

materials can have short- or long-term exposure effects on humans or 
the environment.
    The potential for environmental damage or contamination exists when 
packages of hazardous materia