Hazardous Materials; Combination Packages Containing Liquids Intended for Transport by Aircraft, 38361-38372 [E8-15372]

Agencies

• Pipeline and Hazardous Materials Safety Administration
• DEPARTMENT OF TRANSPORTATION

[Federal Register Volume 73, Number 130 (Monday, July 7, 2008)]
[Proposed Rules]
[Pages 38361-38372]
From the Federal Register Online via the Government Printing Office [www.gpo.gov]
[FR Doc No: E8-15372]


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DEPARTMENT OF TRANSPORTATION

Pipeline and Hazardous Materials Safety Administration

49 CFR Parts 171, 173, and 178

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


Hazardous Materials; Combination Packages Containing Liquids 
Intended for Transport by Aircraft

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

ACTION: Advance notice of proposed rulemaking (ANPRM).

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SUMMARY: PHMSA and the Federal Aviation Administration (FAA) are 
considering changes to requirements in the Hazardous Materials 
Regulations applicable to non-bulk packagings used to transport 
hazardous materials in air transportation. To enhance aviation safety, 
the two agencies are seeking to identify cost-effective solutions that 
can be implemented to reduce incident rates and potentially detrimental 
consequences without placing unnecessary burdens on the regulated 
community. We are soliciting 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 Hazardous Materials 
Regulations (HMR); and (3) authorize alternatives for enhancing package 
integrity. We are also considering ways to simplify current 
requirements. Commenters are also invited to present additional ideas 
for improving the safe transportation of hazardous materials by 
aircraft.

DATES: Comments must be received by September 5, 2008.

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

[[Page 38362]]

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.

SUPPLEMENTARY INFORMATION:

Contents

I. Background
II. Closures and Packages May Fail at High Altitude
III. Analyses of the Problem
    A. FAA Study
    B. United Parcel Service (UPS) Study
    C. Michigan State University (MSU) Study for the Federal 
Aviation Administration (FAA/MSU Study)
    D. MSU Study for PHMSA (PHMSA/MSU Study)
    E. PHMSA Review of Incident Data
IV. Purpose of This ANPRM
    A. Design Qualification and Periodic Retesting
    (1) Pressure Differential Test
    (2) Vibration Testing
    (3) Combination (Simultaneous) Pressure Differential/Vibration 
Testing
    (4) Elimination of Selective Testing Variations
    B. Other Requirements
    (1) Liners and Absorbent Material
    (2) Secondary Means of Closure
V. Questions and Solicitation for Public Comment
    A. Executive Order 12866 and DOT Regulatory Policies and 
Procedures
    B. Executive Order 13132
    C. Executive Order 13175
    D. Regulatory Flexibility Act, Executive Order 13272, and DOT 
Regulatory Policies and Procedures
    E. Information Collection
VI. Regulatory Notices
    A. Executive Order 12866 and DOT Regulatory Policies and 
Procedures
    B. Regulation Identifier Number (RIN)

I. Background

    The Hazardous Materials Regulations (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 hazardous 
materials by aircraft. A combination packaging consists of one or more 
inner packagings secured in a non-bulk outer packaging. (A non-bulk 
outer packaging is one that has a maximum capacity of 450 liters (119 
gallons) as a receptacle for a liquid or a maximum net mass of 400 kg 
(882 pounds) or less and a maximum capacity of 450 liters (119 gallons) 
or less as a receptacle for a solid; see 49 CFR 171.8.) Combination 
packagings are used for the transportation of both solid and liquid 
hazardous materials, including materials such as sodium hydroxide, 
paint, and sulfuric acid and articles such as lithium batteries.
    When used to transport liquid hazardous materials, a combination 
packaging must conform to one of the specifications (i.e., 
``Specification Packaging'') in part 178 of the HMR or an authorized UN 
Standard; the packaging must be tested to ensure that it conforms to 
the applicable specification or standard. Inner packagings within a 
combination packaging must be closed in preparation for testing, and 
tests must be carried out on the completed package in the same manner 
as if prepared for transportation. See 49 CFR 178.602.
    Under the HMR, certain classes and quantities of hazardous 
materials may be transported in non-specification combination 
packagings. A non-specification packaging is not required to meet 
specific performance requirements. Rather, a non-specification 
packaging must meet general packaging requirements. For example, a non-
specification packaging must be designed, constructed, filled, and 
closed so that it will not release its contents under conditions 
normally incident to transportation. In addition, the effectiveness of 
the packaging must be maintained for temperature changes, changes in 
humidity and pressure, and shocks, loadings, and vibrations normally 
encountered during transportation. See 49 CFR 173.24. In addition, a 
non-specification packaging authorized for transportation by aircraft 
must be designed and constructed to prevent leakage that may be caused 
by changes in altitude and temperature. See 49 CFR 173.27. Non-
specification packagings need not be tested to demonstrate that they 
conform to applicable HMR requirements.
    Incident data and testing indicate that a number of combination 
packaging designs authorized for the transportation of liquid hazardous 
materials are not able to withstand conditions normally incident to air 
transportation. The packagings of most concern to PHMSA and FAA are 
non-specification combination 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.
    We are aware that there are a number of contributing factors that 
may cause packaging failures and releases in air transport, including 
non-compliance with existing requirements and lack of function specific 
training of hazmat employees. In this ANPRM, we are soliciting comments 
on cost-effective measures that can be taken to reduce or eliminate the 
number of liquid hazardous materials releases from combination 
packagings in air transport. As discussed in more detail below, PHMSA 
and FAA developed this ANPRM, in part, utilizing data and information 
provided by stakeholders in a meeting on June 21, 2007. PHMSA's review 
of incident data is discussed in section III.E. of this notice. A 
summary of the meeting, including presentations by participants, is 
available for review in the public docket for this rulemaking.
    In 1990, PHMSA's predecessor agency, the Research and Special 
Programs Administration (RSPA), published a final rule under Docket HM-
181 (55 FR 52402; December 21, 1990), revisions and response to 
petitions for reconsideration (56 FR 66124; December 20, 1991) to align 
the HMR with international standards applicable to hazardous materials 
packagings. See 49 CFR part 178, subparts L and M, adopted at 55 FR 
52716-28. That final rule adopted non-bulk hazardous material packaging 
standards based on performance criteria rather than the detailed 
construction specifications that applied prior to 1990 and were phased 
out in 1996. See former 49 CFR 171.14(b)(1), adopted at 55 FR 52473-74. 
Under these performance-oriented packaging requirements, packaging 
strength and integrity are demonstrated through a series of performance 
tests that a packaging must pass before it is authorized for the 
transportation of hazardous materials. The performance criteria provide 
packaging design flexibility that is not possible with detailed design 
specifications.
    In the HM-181 rulemaking, we adopted requirements that all non-bulk 
packaging ``must be capable of withstanding * * * the vibration test 
procedure'' set forth in 49 CFR 178.608 (55 FR at 52727) and that metal 
and plastic and composite packagings ``intended to contain liquids'' 
must pass a hydrostatic pressure test. 49 CFR 178.605 (55 FR at 52726). 
However, we did not adopt our proposal in the notice of proposed 
rulemaking to require a hydrostatic pressure test to be performed on 
all inner packagings of combination packages containing

[[Page 38363]]

liquids intended for transportation by aircraft, which would have 
addressed pressure differentials potentially encountered during air 
transportation. (See 52 FR 16482, May 5, 1987). Instead, consistent 
with the International Civil Aviation Organization Technical 
Instructions for the Safe Transport of Dangerous Goods by Air (ICAO 
Technical Instructions), we adopted a requirement that all packagings 
intended to contain liquids ``must be capable of withstanding without 
leakage'' a specified internal pressure depending on the hazard class/
division and packing group. 49 CFR 173.27(c)(2)(i), adopted at 55 FR 
52612.
    The ICAO Technical Instructions include guidance that indicates in 
more precise terms what is meant by ``being capable,'' but specific 
test methods have not been adopted. The ICAO Technical Instructions 
suggest that the capability of packaging to meet the pressure 
differential performance standard should be determined by testing, with 
the appropriate test method selected based on packaging type. See 
``Note'' following 4.1.1.6.
    The HMR, at 49 CFR 173.27(c), specify that 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 which produces a gauge pressure of not less than 75 
kPa for liquids in Packing Group III of Class 3 or Division 6.1 or 95 
kPa for other liquids; or (2) a pressure related to the vapor pressure 
of the liquid to be conveyed as determined by formulae in subsequent 
paragraphs.

II. Closures and Packages May Fail at High Altitude

    When packages reach high altitudes during transport, they 
experience low pressure on the exterior of the package. 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 will create lower external pressures and, 
therefore, larger pressure differentials. This condition is especially 
problematic for packages containing liquids.
    When a packaging, such as a glass bottle or receptacle, is 
initially filled and sealed, the cap must be tightened to a certain 
level 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 throughout transportation. 
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 may not be the same as when the packaging was initially 
closed. Under normal conditions encountered in air transport (26 kPa @ 
8000 ft), conditions are not overly severe. However, if the compartment 
is depressurized at altitude or if the compartment is not pressurized 
at all (e.g., feeder aircraft), the pressure differential (55 kPa-90 
kPa) may be severe enough to cause package failure and release of 
contents.
    When first closed, and if closed properly, the typical cap and 
bottle do not deform to the point where sealing integrity is 
immediately compromised, although studies have demonstrated that 
plastic bottles and caps do begin to exhibit stress relaxation and a 
reduction in sealing force immediately after the bottles are sealed. 
When the bottle is closed in a manner that accounts for the initial 
stress relaxation of the cap and threads, and there is no altitude 
induced pressure differential in the packaging, no pressure change 
inside the bottle and no change in the spacing between the top of the 
cap and the rim of the bottle, there will be no immediate change in the 
sealing force that affects the bottle's ability to maintain a seal. An 
increase in altitude will cause an increase in the thread contact 
force, but no immediate change in the sealing force. These conditions 
persist for as long as the pressure differential is maintained. Even 
though the sealing force remains unchanged, the increased thread forces 
could distort the cap and cause the cap threads to expand over the 
bottle threads.
    Vibration further complicates the force on the bottle. The net 
effect of the vibration force intermittently compresses and 
decompresses the closure in rapid succession. This can temporarily 
reduce the sealing force to zero. A rapid removal of the compression 
force, which occurs naturally during vibration, may not allow the 
closure to recover quickly enough to maintain a seal. It may take 
several seconds, even minutes, for the closure to return to its 
original configuration, if it returns to the original configuration at 
all. Thus, while the bottle and cap are intermittently compressing and 
decompressing, there may be a gap, which could result in a leak of 
material from the package.
    Finally, the effect of internal pressure and stress relaxation 
after initial closure of the inner receptacle, particularly with 
thermoplastic bottles and caps, can lead to a reduction of sealing 
force on the inner receptacle and may also cause failure of a packaging 
during air transport. Studies reviewed in section III of this notice 
demonstrate that when a thermoplastic bottle and cap are initially 
closed, stress relaxation can account for a reduction of nearly 50% in 
removal torque within minutes of application and an 80% reduction of 
removal torque over several days or weeks. Loss of sealing force due to 
the combination of creep and stress relaxation can also contribute to 
packages leaking in air transportation. As can be understood, the 
combination of stress relaxation, vibration, and low pressure at high 
altitudes may reduce the overall sealing force, thereby compromising 
the closure integrity of a packaging and resulting in leakage from the 
packaging. The air transportation of small parcels typically includes 
multiple flights to reach destination. Therefore, this stress cycle on 
the closure systems of inner packagings repeats itself multiple times 
from origination to destination.

III. Analyses of the Problem

    The following studies simulated the stresses of low external 
pressure and vibration on combination package integrity and performance 
before, during, and while in-flight. These same stresses induced by low 
external pressure and vibration are encountered in-flight when cargo 
and feeder aircraft transport combination packages in non-pressurized 
or partially-pressurized cargo holds. These conditions result in 
substantial changes in pressure when compared to combination packages 
being transported at or near sea level and require a higher level of 
integrity as a result.

A. FAA Study

    In 1999, the FAA began a detailed study of hazardous material 
package failures in air transportation. FAA analyzed incident data from 
the DOT Hazardous Materials Information System (HMIS) during 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. Further study of the spill or leak 
incidents concluded that package closure/seal failure rates were as 
high as 65% for plastic and metal inner packagings and 23% for glass 
inner packagings. All failed inner packagings were packaged in outer UN 
4G marked fiberboard boxes. Based on these study results, FAA concluded 
that either the inner packagings were not

[[Page 38364]]

closed properly as specified in the packaging manufacturer's closure 
instructions or that the inner packagings were not capable of meeting 
the pressure differential requirement or vibration standard of the HMR 
or both. In addition, because the majority (85%) of the materials that 
spilled or leaked during flight were toxic, corrosive or flammable, 
they could have released potentially harmful fumes or vapors into the 
cabin posing a threat to passengers and crew members. FAA determined 
that further research on the actual effects of vibration and pressure 
differential in air transport was warranted.
    As a result of the conclusions of FAA's study of combination 
packaging failures in 2000, FAA conducted extensive laboratory research 
and public outreach in multiple fora to analyze the problem and develop 
potential solutions. Conclusions reached as a result of the following 
laboratory studies indicate problems exist under the current regulatory 
standards for which solutions need to be developed and implemented.

B. UPS Study

    UPS presented a study in 2000 to the American Society of Testing 
and Materials (ASTM) outlining the conditions that packages experience 
in the air transport environment. A copy of the UPS study is available 
for review in the public docket for this rulemaking. The study resulted 
in the following key observations related to air transport as described 
in ASTM D 6653-01:
    1. Aircraft cargo compartments are typically pressurized to an 
altitude of 8,000 ft resulting in a pressure differential of 
approximately 26kPa on packages filled at or near sea level. 
Temperature is maintained at approximately 20[deg]-23 [deg]C (68 [deg]-
74 [deg]F).
    2. Non-pressurized ``feeder aircraft'' typically fly at 
approximately 13,000-16,000 feet. The highest recorded altitude in a 
non-pressurized feeder aircraft was 19,740 ft. Temperatures ranged from 
approximately 4[deg] to 24 [deg]C (25 [deg]-75 [deg]F). Based on these 
findings, it is evident that packaged products transported by the 
feeder aircraft network used by air cargo carriers may experience 
potential altitudes as high as 20,000 feet, resulting in a pressure 
differential of approximately 55 kPa. An inadequate packaging design 
containing liquids at this pressure differential can fail in 
transportation.

C. Michigan State University Study for FAA (FAA/MSU Study)

    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. 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 
the study, the combination packages were placed in various 
orientations, not all of which are authorized in the HMR. The study did 
not include temperature effects because the temperatures in cargo holds 
are not unusual or extreme. Each test condition in Table 1 represents a 
different combination of low pressure and vibration that packages may 
be exposed to while in, or pre- or post-air transport:

                     Table 1.--Ranking of Conditions
------------------------------------------------------------------------
                                                           Percentage of
                                                            failure of
                       Conditions                            packages
                                                              tested
------------------------------------------------------------------------
No vibration, 14,000 ft, 30 min.........................               0
Truck and air vibration, 0 ft, 30 min...................              14
Truck only vibration, 8,000 ft, 180 min.................              21
Truck and air vibration, 8,000 ft, 180 min..............              29
Truck and air vibration (typical sequence for air                     50
 transportation), 14,000 ft, 30 min.....................
------------------------------------------------------------------------

MSU procured 32 design samples of UN standard liquid hazardous material 
combination packagings from three leading hazmat packaging suppliers. 
See United Nations Recommendations on the Transport of Dangerous Goods 
Model Regulations, Volume II, Part 6. The test combination packagings 
were certified to meet current UN, ICAO, and applicable HMR 
requirements. The testing was designed to replicate actual 
transportation conditions. A copy of this report is available for 
review in the public docket. Several key conclusions can be drawn from 
the analysis:
     UN standard liquid hazardous material combination 
packagings leaked under a combined vacuum and vibration test which 
simulated the characteristics of air transportation and high altitude.
     One study concluded laboratory testing for pressure 
differential capability without exposure to vibration may not be a 
realistic replication of the air transportation environment. When both 
forces are applied to a package simultaneously, the failure rate 
increases to 50%.
     Altitude is more important than the length of time in 
flight; higher altitude is more severe than lower altitude.
     Results of combined truck and air vibration are more 
severe than truck vibration alone.
     Vibration periodically reduces the sealing force on a 
liner or gasket and may produce intermittent gaps that open and close 
at concentrated pressure points.
     The study was based on the conditions normally encountered 
by a package in truck and air transport.

D. Michigan State University Study for PHMSA (PHMSA/MSU Study)

    In 2003, PHMSA also initiated a study with MSU to compare the HMR 
requirements and the testing used in the FAA/MSU Study discussed 
previously. To provide for a more thorough evaluation of the 
performance of liquid hazardous materials combination packagings, this 
phase of testing was conducted on a smaller number of packaging 
designs; however, a much greater number of packagings of each design 
were tested in this study. In the 2002 FAA/MSU study, two packagings of 
each design were tested; for this study, PHMSA tested thirty packagings 
from each of eleven designs. With the exception of three packaging 
designs, all of the packagings tested during this phase had been tested 
for the 2002 FAA/MSU study. See Table 2 below. A copy of this report is 
available for review in the public docket.

                     Table 2.--Ranking of Conditions
------------------------------------------------------------------------
                                                           Percentage of
                                                            failures of
                       Conditions                            packages
                                                              tested
------------------------------------------------------------------------
Random vibration and vacuum, vertical orientation                     12
 (conforming to HMR), 14,000 ft, one hour...............
Random vibration and vacuum, horizontal orientation,                  18
 14,000 ft, one hour....................................
Vacuum only, 95 kPa for 30 min, inverted orientation....              13
Random vibration, one hour..............................              11
 
    Average failure rate................................              13
------------------------------------------------------------------------

    The conclusions from this testing supported MSU's previous testing 
conducted for FAA:
     Packages performed unsatisfactorily when tested in the 
orientation required by the HMR; when the packages were oriented 
improperly, the leakage rate was even greater.
     Proper package orientation is a critical factor in 
reducing leaks from packages.

[[Page 38365]]

     UN standard combination packagings did not pass the 
combined pressure differential and random vibration while in the HMR 
required orientation. Of the 99 bottles subjected to this test, 87 
successfully passed the test.
     Laboratory package failure rate is greater than 10% and 
would be considered unacceptable based on industry standards with a 
lower safety risk (i.e., non-hazmat packagings). Acceptable failure 
rates for consumer products is less than 5%; electronics is less than 
1%; food/pharmaceutical less than 3-5%; the average failure rate of 
this controlled study was 13%.
     Packages that utilized a secondary means of closure had a 
lower rate of failure.
     Testing in a horizontal orientation that simulated air 
transport combining random vibration and a pressure differential 
(vacuum) of 59.5 kPa (14,000 ft), for one hour, resulted in an 18% 
failure rate.

E. PHMSA Review of Incident Data

    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 are transported by 
aircraft annually contained in 7,657,152 combination packaging 
shipments. Of that total, our analysis concluded that out of 
approximately 483 failures (.00006%) in air transportation involving 
combination packagings containing liquids each year, 20 are reported as 
``serious.'' An incident is considered serious if it 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; and (7) the 
release of a bulk quantity (over 450 liters (119 gallons) or 400 
kilograms (882 pounds)) of a hazardous material. We want to emphasize 
that any incident, such as a package failure, involving hazardous 
materials in air transportation is unacceptable. In air transportation, 
any incident could quickly escalate and result in irreversible, 
possibly catastrophic, consequences.
    Accounting for approximately 80 percent of all packages transported 
by air, combination packagings containing liquids are involved in 44 
percent (483) of all package failures annually. Inner packaging closure 
failures within a combination outer packaging are the primary cause of 
incidents involving combination packagings in air transportation. Such 
failures could be the result of pressure differential (packages closed 
at sea level subjected to lower pressure on planes), ``backing off'' of 
the closure (closures that appear tight but loosen during 
transportation), improper closures, or some other cause. Our analysis 
also suggests that most incidents involve combination packagings that 
contain flammable liquids (e.g., paint and paint related material) of 
varying degrees of hazard. Some additional statistical data from the 
2007 incident review include:
     Incident trends are similar to earlier FAA studies.
     Laboratory research validates the conclusion that inner 
receptacles (e.g., bottles and caps) leak as indicated in the incident 
data.
     Leaking (failing) closures and inner receptacles are not 
the leading cause of incidents in air transportation; however, over 40% 
of combination packages containing liquids that fail in air 
transportation do involve closures and inner receptacles.
     Flammable liquids are the most common liquid hazardous 
materials released from failed packages in air transportation. Such 
materials or its vapor would seek and could find an ignition source 
resulting in fire or explosion.
     In 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 
failure continues to be a troubling statistic.
     Combination packages containing liquids that fail in air 
transportation release on average 0.5 gallons of liquid hazardous 
materials.
    PHMSA presented the results of this review at a June 21, 2007 
meeting with stakeholders to discuss air packaging issues. The 44 
participants included cargo and passenger air carriers, packaging 
manufacturers and testing laboratories, FAA and PHMSA personnel, and 
representatives of industry trade associations. The shippers, air 
carriers, and enforcement personnel present generally agreed that the 
current capability requirements for air packagings are difficult to 
comply with and suggested that specific test methods designed to 
demonstrate that packagings will withstand the air transportation 
environment should be specified in the HMR.
    Stakeholders at the meeting also suggested that increased outreach 
through industry partnership and targeted enforcement for habitual 
offenders would significantly enhance achievement of PHMSA and FAA 
safety goals without additional regulation.

IV. Purpose of This ANPRM

    As previously noted, to enhance aviation safety, PHMSA and FAA are 
seeking to identify cost-effective solutions that can be implemented to 
reduce incident rates and potentially detrimental consequences without 
placing unnecessary burdens on the regulated community. We are 
soliciting 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. Based on PHMSA and FAA analyses, it 
appears that some combination packaging designs used to transport 
hazardous materials by aircraft may not meet the pressure differential 
and vibration capability standards mandated under the HMR. Indeed, the 
testing 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. 
Because aircraft accidents caused by leaking or breached hazardous 
materials packages can have significant consequences, the air transport 
of hazardous materials requires exceptional care and attention to 
detail. Therefore, we are considering measures to reduce the incidence 
of package failures and to minimize the consequences of failures should 
they occur.
    The fact that specific test methods are not specified in the HMR or 
the ICAO Technical Instructions leads to inconsistencies in package 
integrity and results in varying levels of compliance among shippers. 
For example, we understand that, because the pressure differential and 
vibration capability standards for combination packagings are not 
required to be verified by a test

[[Page 38366]]

protocol, 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. Further, some less experienced shippers or manufacturers may 
not understand that their packagings must withstand pressure 
differential and vibration requirements. In addition, some shippers or 
manufacturers may not realize that both UN Standard packaging and 
packagings that are not required to be certified as meeting a 
specification or standard are subject to the pressure differential 
capability requirement. This would include packagings for products, 
such as limited quantities and consumer commodities, where non-
specification packagings are authorized. A significant percentage of 
aircraft incidents involving hazardous materials appear to result from 
failures of non-specification packagings.
    As indicated above, a non-specification packaging is not required 
to meet specific performance requirements. Rather, a non-specification 
packaging must meet general packaging requirements and, for air 
transportation, must be capable of withstanding pressures encountered 
at altitude. We invite comments on how to enforce this ``capability'' 
standard for non-specification packagings and ask whether a test of 
some sort should be required to verify packaging integrity.
    A complicating factor that appears to be contributing to packaging 
failures and non-compliance is that assembly of packages in some cases 
is not consistent with the design type that was originally tested. In 
some cases, manufacturers change components without informing the 
shipper; in other cases, shippers specify or change components without 
appropriate verification and testing to determine compliance with the 
applicable performance standard. The numerous variables that exist in 
the interaction of closures, liners, and container neck finishes 
preclude the use and validity of general assumptions about equivalent 
pressure performance capabilities of similar containers.
    As an alternative to regulation, the FAA implemented an aggressive 
public outreach program over the past seven years targeted at specific 
stakeholder audiences, including thousands of shippers, packaging 
laboratories, industry research and training institutes, airline 
operators, and chemical manufacturers. In addition, several voluntary 
industry standards (test protocols) were either created or revised as a 
result of the public (independent) and private funding of the studies 
detailed in the previous sections above. A copy of the report listing 
the specific public outreach efforts conducted by FAA on this issue can 
be found in the docket for this rulemaking.
    Some regulatory solutions under consideration in this rulemaking 
process are explained in more detail in the following sections.

A. Design Qualification and Periodic Retesting

    (1) Pressure differential test. Currently in the HMR, all 
packagings containing liquids and intended for transport by air must 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 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 49 CFR 
173.27(c)). This requirement is also applicable to liquids excepted 
from specification or UN Standard packaging, such as those authorized 
for limited quantities and consumer commodities. This would include 
eligible liquids of Classes 3 (flammable) and 8 (corrosive), and 
Divisions 5.1 (oxidizer), 5.2 (organic peroxide), and 6.1 (poisonous). 
Liquids contained in inner receptacles that do not meet the minimum 
pressure requirements in the current Sec.  173.27(c) may be overpacked 
into receptacles that do meet the pressure requirements.
    In this ANPRM, we are soliciting comments on whether we should 
require mandatory pressure differential testing for all specification 
or UN Standard combination packaging designs containing liquids 
transported or intended for transportation aboard aircraft. In 
addition, because many incidents are attributed to non-specification 
package failures, we are soliciting comments on potential solutions to 
this problem that may or may not include the mandatory pressure 
differential testing of inner receptacles intended to contain liquids. 
One approach would be to incorporate by reference a number of 
acceptable test methods and to simplify the regulations by removing the 
requirement for calculating the test pressure in Sec.  173.27(c). 
Shippers (offerors) would be responsible for using inner receptacles 
that have been certified as passing one of the following test methods:

----------------------------------------------------------------------------------------------------------------
                 Test                         Equipment           Time under pressure     Pressure differential
----------------------------------------------------------------------------------------------------------------
(a) 49 CFR 178.605...................  Pressure fitting, pump.  5 minutes for metal and  60 kPa differential.
                                                                 composite (including
                                                                 glass, porcelain, or
                                                                 stoneware); 30 minutes
                                                                 for plastic.
(b) ASTM D6653-01....................  Vacuum chamber and       60 minutes.............  14,000 ft (41.8 kPa
                                        associated gages and                              differential) \1\ or
                                        pumps.                                            16,000 ft (46.4 kPa
                                                                                          differential).\2\
(c) ASTM D4991-94....................  Transparent vessel       30 minutes for plastic,  60 kPa pressure
                                        capable of               10 minutes for           differential.
                                        withstanding 1\1/2\      everything else.
                                        atmospheres, inlet
                                        tube and vacuum pump,
                                        moisture trap,
                                        solution of ethylene
                                        glycol in water.
(d) ASTM F1140 or Part 178 Appendix D  Inlet tube.............  30 minutes.............  60 kPa pressure
 for flexible packaging.                                                                  differential.
----------------------------------------------------------------------------------------------------------------
\1\ If it is not possible to use the atmospheric and temperature pre-conditioning specified.
\2\ For test specimens where the atmospheric and temperature pre-conditioning is followed.

    (a) 49 CFR 178.605--Low Pressure Hydrostatic Pressure Test Method 
Suitable for Air Inner Packages. This test is currently required for 
all single and composite packagings intended to contain liquid, but it 
is not currently required for inner packagings of combination 
packaging. This test, which uses the hydrostatic test method, pumps 
high-pressure water into a packaging to create a pressure differential. 
Failure is determined if there is leakage of liquid

[[Page 38367]]

from the package during the test. This could be observed as a stream of 
liquid exiting the package or rupture of the package.
    (b) ASTM D6653-01--Standard Test Methods for Determining the 
Effects of High Altitude on Packaging Systems by Vacuum Method. This 
method uses a vacuum chamber to determine the effects of pressure 
differential on packages. Upon completion of the test, the package is 
removed and checked for damage in the form of package failure, closure 
failure, material failure, internal packaging failure, product failure, 
or combinations thereof. If these are all free of damage, then the 
packaging should be reassembled for testing in accordance with an 
industry accepted packaged product performance test, such as Practice D 
4169. This will help determine if the pressure differential 
conditioning had an effect on the performance of the packaging system.
    (c) ASTM D4991-94 (Re-approved 1999) Standard Test Method for 
Leakage Testing of Empty Rigid Containers by Vacuum Method. This test 
is applied to empty packagings to check for resistance to leakage under 
differential pressure conditions, such as those that can occur during 
air transport. Instead of pumping high-pressure air into the packaging, 
the air pressure on the exterior of the packaging is reduced using a 
vacuum. The package is considered to fail if it leaks a continuous 
stream or recurring succession of bubbles or if fluid is found within 
the test specimen after the test.
    (d) ASTM F 1140--Standard Test Methods for Internal Pressurization 
Failure Resistance of Unrestrained Packages for Medical Applications. 
This test applies to flexible packaging (e.g., bags).
    (2) Vibration testing. When packages travel through the 
transportation and distribution environment, they are subject to 
vibration by automated sorting systems and during transit aboard 
aircraft, railcars, or trucks. As packages move on conveyor systems 
during automated sorting, they experience a low level of vibration at a 
constant frequency. Aircraft-induced vibration typically is very high 
frequency and low amplitude for 30 minutes to 12 hours on domestic 
shipments, depending on origin, destination, and the carrier's network. 
Vibration on trucks occurs at lower frequencies, but at much higher 
amplitudes than on aircraft. This duration can last anywhere from 5 
minutes to several days depending upon the route and the distance from 
origin to destination. Vibrations from these various sources can result 
in damage, including scuffing, abrasion, loosening of fasteners and 
closures, and package fatigue. There are two main types of vibration 
testing used for packages: Fixed frequency vibration and random 
vibration. Random vibration provides the most realistic representation 
of actual transport conditions, but requires equipment that is more 
expensive.
    The HMR require non-bulk packagings to be capable of withstanding, 
without rupture or leakage, the vibration test in 49 CFR 178.608. In 
this ANPRM, we are soliciting comments concerning whether the HMR 
should be revised to require all specification or UN Standard 
combination packaging design types containing liquids transported or 
intended to be transported aboard aircraft to be vibration tested and 
whether alternative vibration test methods should be authorized for 
non-bulk packagings. We invite comments on whether the random vibration 
encountered during the ``sorting'' process and multiple flight segments 
of today's expedited shipping environment contributes to package 
failure and whether more representative vibration test methods should 
be specified in the HMR.
    Alternative test methods for determining package vibration 
capability are described in the following table:

----------------------------------------------------------------------------------------------------------------
              Test                       Title             Equipment           Frequency             Time
----------------------------------------------------------------------------------------------------------------
                                     Vertical Linear Test at Fixed Frequency
----------------------------------------------------------------------------------------------------------------
ASTM D999-01 Method A1..........  Repetitive Shock    Vibration test      Start vibration at  Predetermined
                                   Test (Vertical      machine with        2 Hz and steadily   time, as stated
                                   Motion).            horizontal          increase until      in applicable
                                                       surface and         the test specimen   specification, or
                                                       mechanism for       repeatedly leaves   until
                                                       vertical            the test surface.   predetermined
                                                       sinusoidal input;                       amount of damage
                                                       fences,                                 is detected.
                                                       barricades or
                                                       other restraints.
ASTM D999-01 Method A2..........  Repetitive Shock    Vibration test      Start vibration at  Predetermined
                                   Test (Rotary        machine with        2 Hz and steadily   time, as stated
                                   Motion).            horizontal          increase until      in applicable
                                                       surface and         the test specimen   specification, or
                                                       mechanism for       repeatedly leaves   until
                                                       rotational input    the test surface.   predetermined
                                                       with a vertical                         amount of damage
                                                       component                               is detected.
                                                       approximately
                                                       sinusoidal;
                                                       fences,
                                                       barricades or
                                                       other restraints.
ASTM 4169-04a Paragraph 13.1      Loose Load          Use Test Method     Use Test Method     Assurance Level I:
 (Schedule F).                     Vibration           ASTM D999, Method   ASTM D999, Method   60 min dwell
                                   (Repetitive         A1 or A2.           A1 or A2.           time; Assurance
                                   Shocks).                                                    Level II: 40 min
                                                                                               dwell time;
                                                                                               Assurance Level
                                                                                               III: 30 min dwell
                                                                                               time.
49 CFR 178.608..................  Repetitive Shock    Vibration platform  A frequency that    60 minutes.
                                   Test (Vertical or   that has a          causes the
                                   Rotary Motion).     vertical or         package to be
                                                       rotary double-      raised from the
                                                       amplitude (peak-    vibrating
                                                       to-peak             platform to such
                                                       displacement) of    a degree that a
                                                       one inch.           piece of material
                                                                           of approximately
                                                                           1.6 mm thickness
                                                                           can be passed
                                                                           between the
                                                                           bottom of any
                                                                           package and the
                                                                           platform.
----------------------------------------------------------------------------------------------------------------

[[Page 38368]]

 
                                   Vertical Linear Test at Variable Frequency
----------------------------------------------------------------------------------------------------------------
ASTM D999-01 Methods B & C......  Resonance Tests...  Vibration test      Find the resonant   Dwell for
                                                       machine with        frequency of the    specified length
                                                       horizontal          package using       of time at each
                                                       surface and         either the sine     resonant
                                                       mechanism for       sweep method or     frequency
                                                       vertical            the random          determined
                                                       sinusoidal input;   vibration input     earlier or until
                                                       suitable fixtures   method. The         damage to the
                                                       and attachment      minimum frequency   packaging is
                                                       points to rigidly   range should be     noted. If no
                                                       attach the test     from 3 to 100 Hz.   dwell time is
                                                       packaging to the                        specified, 15
                                                       platform;                               minutes is
                                                       instrumentation.                        recommended.
----------------------------------------------------------------------------------------------------------------
                                              Random Vibration Test
----------------------------------------------------------------------------------------------------------------
ASTM 4728-01....................  Random Vibration    Vibration table     Frequency is        Predetermined
                                   Testing.            supported by a      determined by       time, as stated
                                                       mechanism capable   power spectral      in applicable
                                                       of producing        density (PSD)       specification, or
                                                       single axis         profile.            until
                                                       vibration; inputs                       predetermined
                                                       at controlled                           amount of damage
                                                       levels of                               is detected.
                                                       continuously
                                                       variable
                                                       amplitude
                                                       throughout the
                                                       desired range of
                                                       frequencies;
                                                       suitable fixtures
                                                       to restrict
                                                       undesired
                                                       movement; closed
                                                       loop controller
                                                       or data storage
                                                       media open loop
                                                       control systems;
                                                       instrumentation.
ASTM 4169-04a Paragraph 12.4      Random Test Option  See Test Method     Frequency is        For Distribution
 (Schedule D and E).                                   ASTM 4728 Method    determined by       Cycles 12 and 13,
                                                       A or B.             power spectral      a 60-minute truck
                                                                           density (PSD)       test followed by
                                                                           profile.            a 120-minute air
                                                                           Frequency ranging   test.
                                                                           from 2-300 Hz for
                                                                           air mode.
----------------------------------------------------------------------------------------------------------------

    (a) ASTM D999-01: Standard Test Methods for Vibration Testing of 
Shipping Containers
    (b) ASTM D4169 04a Paragraph 12.4 or Paragraph 13.1: Standard 
Practice for Performance Testing of Shipping Containers and Systems
    (c) ASTM D4728-01: Standard Test Method for Random Vibration 
Testing of Shipping Containers
    (3) ``Combination'' Pressure Differential and Vibration Tests. In 
this ANPRM, we are soliciting comments concerning whether sequential 
pressure and vibration testing are sufficient to ensure packaging 
integrity, i.e., a ``combination'' of both pressure and vibration 
testing. The vibration testing would be followed by pressure testing, 
which is considered less severe than simultaneous testing, which 
subjects a packaging to vibration and pressure at the same time. 
Simultaneous testing under the combination test standards involves 
rather sophisticated, extensive, and expensive equipment, and 
relatively skilled operators. In this ANPRM we are soliciting comment 
on whether these methods should be authorized, given our understanding 
that a number of companies are already voluntarily applying these 
tests. We invite commenters to address successful completion of these 
tests as an alternative means of compliance with existing pressure 
differential and vibration capability requirements.
    The following three combination tests are voluntary industry 
standards that we may consider as alternatives for conducting vibration 
testing and pressure differential testing on the same inner packaging:

----------------------------------------------------------------------------------------------------------------
 
----------------------------------------------------------------------------------------------------------------
(a) ISTA 3A..........................  Individual packaged       Atmospheric     The section for random
                                        products weighing 150    Preconditioning.         vibration under
                                        lbs. or less; air or     Shock (drop)..   pressure is optional.
                                        ground transportation.   Vibration        When conducted, the
                                                                 (random with and         pressure and vibration
                                                                 without top load).       are simultaneous. A
                                                                 Vibration        pressure approximately
                                                                 (random under vacuum).   equal to an altitude
                                                                 Shock (drop)..   of 10,000 ft. is used
                                                                                          for 60 minutes.
(b) ASTM 4169 Distribution Cycle 12..  Air (intercity) and       Handling......  Low-pressure section
                                        motor freight (local),   Stacked          instructs packages to
                                        over 100 lb., unitized.  Vibration..              be tested at pressure
                                                                 Low-Pressure..   of expected altitudes.
                                                                 Vehicle          If not known, refer to
                                                                 Vibration and            ASTM D6653, which
                                                                 Handling..               specifies 14,000 ft.
                                                                                          for 60 minutes. See
                                                                                          ASTM 4169 for
                                                                                          vibration details.

[[Page 38369]]

 
(c) ASTM 4169 Distribution Cycle 13..  Air (intercity) and       Handling......  Low-pressure section
                                        motor freight (local),   Vehicle          instructs packages to
                                        single package up to     Stacking..               be tested at pressure
                                        100 lb.                  Loose-Load       of expected altitudes.
                                                                 Vibration..              If not known, refer to
                                                                 Low-Pressure..   ASTM D6653, which
                                                                 Vehicle          specifies 14,000 ft.
                                                                 Vibration and            for 60 minutes. See
                                                                 Handling..               ASTM 4169 for
                                                                                          vibration details.
----------------------------------------------------------------------------------------------------------------

    (a) ISTA 3A--This is part of a series of general simulation tests 
that are meant to recreate the hazards of a distribution environment. 
It is similar to ASTM 4169 because it requires rather sophisticated, 
extensive, and expensive equipment (such as a random vibration table 
with appropriate instrumentation) and relatively skilled operators. 
Unlike D4169, however, there are a number of specific procedures, 
covering a number of packaged products and distribution systems, so 
much less interpretation is required. This procedure includes shock and 
vibration testing with an option to include simultaneous pressure 
testing during one of the random vibration phases.
    (b) ASTM 4169 Distribution Cycle 12--This is the only ASTM standard 
devoted to packaged product performance in distribution. It is a pre-
shipment general simulation test covering a range of packaging types 
and distribution scenarios. For example, it lists 18 distribution 
cycles that each represents a different mode or environment. There is a 
prescribed sequence of performance tests for each of these distribution 
cycles. Air transportation is covered in Distribution Cycles 12 and 13. 
These cycles include several types of vibration and pressure testing. 
However, these are performed sequentially, unlike ISTA 3A, which has 
the option to perform vibration and pressure testing simultaneously. 
Distribution Cycle 12 tests are for unitized freight that weighs over 
100 lbs. More details on the sequence of testing can be found in the 
previous table.
    (c) ASTM 4169 Distribution Cycle 13--Distribution Cycle 13 tests 
are for loose-load freight weighing under 100 lbs. The prescribed tests 
specify an additional vibration test to simulate the more aggressive 
shipping environment. More details on the sequence of testing can be 
found in the previous table.
    (4) Elimination of Selective Testing Variations. The HMR currently 
provide selective testing variations--that is, inner packagings that 
differ in only minor respects from a tested inner packaging design type 
may be used without further testing under the conditions specified in 
49 CFR 178.601(g) (selective testing variation 1). In this ANPRM, we 
invite commenters to address whether this variation should be revised, 
restricted or eliminated for packagings intended for air 
transportation. In addition, we are concerned that the use of different 
components (e.g., bottle, cap, liner) than what were originally tested 
may result in less than effective closure systems and may result in 
packagings that are not representative of the originally tested design 
type. The numerous variables that exist in the interaction of closures, 
liners and container neck finishes are complex and the use and validity 
of general assumptions about equivalent pressure performance 
capabilities of similar containers is not straightforward. On the basis 
of compliance reviews and incident investigations, we believe that this 
selective testing provision may result in the use of packaging systems 
that are not capable of withstanding conditions encountered in air 
transport and at high altitude. Changes in quality control measures and 
materials may also adversely affect packaging performance. For example, 
changing the type of resin used in plastic bottle manufacturing can 
significantly contribute to the ability of the packaging system to 
perform as intended. Packaging manufacturers may not readily recognize 
the complexity and importance of controlling component and 
manufacturing variations. We invite comments on how best to address 
this issue and whether certain changes in packaging components or 
variations in materials of construction should be reevaluated or tested 
and retested as a new design.

B. Other Requirements

    (1) Liners and Absorbent Material. Packages containing liquid 
hazardous materials must include a method for containing the liquid, 
whether it is a leak-proof liner, plastic bag, absorbent material or 
other equally effective means. Liners are currently required in the 
following circumstances:
     Packages containing certain types of hazardous materials 
liquids (e.g., Class 3, 4, or 8, or Division 5.1, 5.2, or 6.1) when 
absorbent materials are required and the outer packagings are not 
liquid-tight and transported by aircraft (49 CFR 173.27(e)).
     Either the inner or outer packagings when mercury is 
transported by aircraft (49 CFR 173.164).
    It is our understanding, based on discussions with shippers, that 
many shippers already use protective liners with liquid hazardous 
materials packages. These shippers suggest that liners are included 
only if the packages are intended for transportation by air. However, 
many of th