Hazardous Materials Regulations: Aluminum Cylinders Manufactured of Aluminum Alloy 6351-T6 Used in SCUBA, SCBA, Carbon Dioxide, and Oxygen Service-Revised Requalification and Use Criteria, 61762-61769 [05-21273]

Agencies

• Pipeline and Hazardous Materials Safety Administration
• DEPARTMENT OF TRANSPORTATION

[Federal Register Volume 70, Number 206 (Wednesday, October 26, 2005)]
[Proposed Rules]
[Pages 61762-61769]
From the Federal Register Online via the Government Printing Office [www.gpo.gov]
[FR Doc No: 05-21273]


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DEPARTMENT OF TRANSPORTATION

Pipeline and Hazardous Materials Safety Administration

49 CFR Parts 173 and 180

[Docket No. PHMSA-03-14405 (HM-220F)]
RIN 2137-AD78


Hazardous Materials Regulations: Aluminum Cylinders Manufactured 
of Aluminum Alloy 6351-T6 Used in SCUBA, SCBA, Carbon Dioxide, and 
Oxygen Service--Revised Requalification and Use Criteria

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

ACTION: Supplemental notice of proposed rulemaking.

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SUMMARY: On September 10, 2003, the Research and Special Programs 
Administration--the predecessor agency to the Pipeline and Hazardous 
Materials Safety Administration published a notice of proposed 
rulemaking (NPRM) to propose an inspection and testing program for 
early detection of sustained load cracking in certain cylinders 
manufactured with aluminum alloy 6351-T6. Based on comments received in 
response to that NPRM, we are proposing to adopt a maximum service life 
for cylinders manufactured with aluminum alloy 6351-T6 and to prohibit 
the use of these cylinders after the expiration of their maximum 
service life.

DATES: Comments must be received by December 27, 2005.

ADDRESSES: You may submit comments to Docket No. PHMSA-03-14405 (HM-
220F) by any of the following methods:
     Federal eRulemaking Portal: Go to https://
www.regulations.gov. Follow the online instructions for submitting 
comments.
     DOT Web site: https://dms.dot.gov. To submit comments on 
the DOT electronic docket site, click ``Comment/Submissions,'' click 
``Continue,'' fill in the requested information, click ``Continue,'' 
enter your comment, then click ``Submit.''
     Fax: 202-493-2251.
     Mail: Docket Management System; U. S. Department of 
Transportation, 400 Seventh Street, SW., Nassif Building, Room PL-401, 
Washington, DC 20590-0001.
     Hand Delivery: Docket Management System; Room PL-401 on 
the plaza level of the Nassif Building, 400 Seventh Street, SW., 
Washington, DC, between 9 a.m. and 5 p.m., Monday through Friday, 
except Federal holidays.

[[Page 61763]]

    Instructions: You must include the agency name and docket number 
PHMSA-03-14405 (HM-220F) or the Regulatory Identification Number (RIN) 
for this notice at the beginning of your comment. You should submit two 
copies of your comments if you submit them by mail. If you wish to 
receive confirmation that we received your comments, you must include a 
self-addressed stamped post card. Note that all comments received will 
be posted without change to https://dms.dot.gov including any personal 
information provided. Please see the Privacy Act section of this 
document.

FOR FURTHER INFORMATION CONTACT: Mark Toughiry, Office of Hazardous 
Materials Technology, (202) 366-4545, or Kurt C. Eichenlaub, Office of 
Hazardous Materials Standards, (202) 366-8553; PHMSA, U.S. Department 
of Transportation, 400 Seventh Street SW., Washington, DC 20590-0001.

SUPPLEMENTARY INFORMATION:

Contents

I. Background
II. Previously Published NPRM
III. Analysis of Comments
IV. Proposals in This SNPRM
V. Section-By-Section Review
VI. Regulatory Analyses and Notices
    A. Statutory/Legal Authority for This Rulemaking
    B. Executive Order 12866 and DOT Regulatory Polices and 
Procedures
    C. Executive Order 13132
    D. Executive Order 13175
    E. Regulatory Flexibility Act, Executive Order 13272, and DOT 
Procedures and Policies
    F. Paperwork Reduction Act
    G. Regulation Identifier Number (RIN)
    H. Unfunded Mandates Reform Act
    I. Environmental Assessment
    J. Privacy Act
List of Subjects

I. Background

    Cylinders made of aluminum alloy 6351-T6 are known to be 
susceptible to sustained load cracking (SLC) in the neck and shoulder 
area of the cylinder. The majority of SLC-related ruptures have 
occurred in self-contained underwater breathing apparatus (SCUBA), 
self-contained breathing apparatus (SCBA), and oxygen services. Since 
1994, the Pipeline and Hazardous Materials Safety Administration 
(PHMSA, we) has been notified of thirteen suspected SLC ruptures of 
cylinders manufactured of aluminum alloy 6351-T6. Five of the thirteen 
ruptures resulted in serious injuries. Data from manufacturers show 
there are thousands of cylinders with small, non-leaking cracks, that 
are regularly detected during a diligent, proper requalification 
process. Manufacturers of cylinders made from the 6351-T6 aluminum 
alloy have performed research, testing and analysis to determine 
whether there is any correlation between SLC and the probability of a 
cylinder rupture. The data indicated the cylinders would leak but not 
rupture when operated at marked service pressure. It was also found the 
probability of cracking increases with an increase in stress levels. We 
performed additional metallurgical analysis on several ruptured 
cylinders to verify the cause of failure and failure mode. (See the 
metallurgical analysis reports at https://hazmat.dot.gov/pubs/reports/
cylinder/3al_cyls_info.htm). Those metallurgical analyses revealed 
SLC caused the cylinder ruptures, but the results were inconclusive as 
to why the cylinders abruptly ruptured instead of developing leaks. 
United States manufacturers discontinued using aluminum alloy 6351-T6 
in the mid-1990s, replacing it with aluminum alloy 6061-T6, which is 
not susceptible to SLC. Cylinders manufactured of aluminum alloy 6351-
T6 prior to July 1990 include seamless aluminum cylinders marked ``DOT 
3AL'', including those marked with ``DOT 3AL'' above or near one of the 
following exemption or special permit numbers: 6498, 7042, 8107, 8364, 
and 8422. We estimate approximately six million U.S. cylinders 
manufactured from aluminum alloy 6351-T6 are currently in use in SCUBA, 
SCBA, Carbon Dioxide (CO 2), and oxygen services.
    The primary domestic manufacturers of DOT 3AL cylinders currently 
in service are Luxfer USA; Walter Kidde Co.; Cliff Impact Division of 
Parker Hannifin Corporation; and Catalina Cylinders. The majority of 
the cylinders are being used in six major services: (1) SCUBA, (2) 
SCBA, (3) CO 2, (4) oxygen, (5) industrial gases, and (6) 
fire extinguishers.
    On August 8, 2002, we published a final rule (Docket HM-220D, 67 FR 
51626) amending the requirements of the Hazardous Materials Regulations 
(HMR; 49 CFR parts 171-180) applicable to the maintenance, 
requalification, repair, and use of DOT specification cylinders. On May 
8, 2003, we issued a subsequent final rule (68 FR 24653) that made 
further revisions in response to appeals. In the final rule and the 
response to appeals, we added the following amendments pertaining to 
DOT specification cylinders made with aluminum alloy 6351-T6:
     Removed the authorization for the manufacture of DOT 
specification cylinders from aluminum alloy 6351-T6 because cylinders 
manufactured with this aluminum alloy have a greater risk of failure 
than other aluminum cylinders.
     Prohibited these cylinders for Hazard Zone A materials 
effective on October 1, 2002. After that date, cylinders made of 
aluminum alloy 6351-T6 may not be filled and offered for transportation 
in toxic inhalation hazard service.
     Prohibited the use of cylinders manufactured of aluminum 
alloy 6351-T6 for gases having pyrophoric properties.
     Required a visual inspection of DOT specification or 
exemption cylinders made of aluminum alloy 6351-T6 for evidence of SLC 
in the neck and shoulder area.
    The HMR require DOT 3AL cylinders to be requalified every five 
years (twelve years for fire extinguishers) in accordance with Sec.  
180.205. The requalification performed under Sec.  180.205 includes a 
visual inspection (internal and external) and a volumetric expansion 
test. During the visual inspection, cylinders must be inspected for 
evidence of SLC in the neck and shoulder area. However, we understand 
that in addition to the visual inspection and volumetric expansion 
test, many users and requalifiers are currently performing an eddy 
current examination. Approximately 2,000 eddy current devices have been 
purchased by various technicians in the dive, fire and cylinder 
requalification industries to examine aluminum cylinders for SLC. 
Cylinder manufacturers report that a large number of affected cylinders 
have been removed from service because of flaws discovered during eddy 
current examinations.

II. Previously Published NPRM

    On September 10, 2003, the Research and Special Programs 
Administration, the predecessor agency to the PHMSA, published an NPRM 
proposing to amend HMR requirements on aluminum cylinders manufactured 
using aluminum alloy 6351-T6. The NPRM proposed a standard for early 
detection of SLC to reduce the risk of a cylinder rupture.
    We evaluated the following three non-destructive examination (NDE) 
techniques--internal visual examination (VE), eddy current examination 
(EE), and ultrasonic examination (UE)--to detect a critical-size crack. 
A cylinder with a critical-size crack would be removed from service. 
Under the direction of PHMSA, Texas Research Institute (TRI) evaluated 
these three NDE (VE, EE, UE) methods by performing blind examinations 
applied

[[Page 61764]]

by individuals of varying skill levels (See the Nondestructive 
Inspection of High Pressure Aluminum Gas Cylinder, Final Report, dated 
September 2000, at https://hazmat.dot.gov/enforce/forms/ohmforms.htm). 
TRI determined that each NDE method was capable of detecting SLC, but 
detection using VE was limited by external factors, such as the 
inspector's eye sight, lighting, position of the crack, and alertness 
of the examiner. TRI also determined that UE must be applied by a 
certified technician to produce accurate results in detecting SLC. TRI 
concluded EE combined with a VE provides the most accurate and 
practical examination for detecting SLC. Both EE and VE can be 
conducted by a requalifier with minimal training.
    In the NPRM, for cylinders manufactured of aluminum alloy 6351-T6 
used in SCUBA (diving), SCBA (firefighting), and oxygen service, we 
proposed the following amendments:
     Require cylinders to undergo a combined visual and eddy 
current examination.
     Add a new Appendix C to Part 180, to specify the procedure 
to conduct the eddy current examination.
     That suitable safeguards be provided to protect personnel 
and facilities should a cylinder fail during the filling process.
     That only individuals essential to the filling process be 
allowed in the vicinity of the cylinder during the filling process.
    Although we believe the thirteen reported SLC ruptures under-
represent the extent of the SLC issue, we did not have sufficient data 
to determine whether the SLC-related ruptures extend beyond those 
services discussed above. Therefore, we requested additional 
information from manufacturers and users who were aware of the rupture 
of any DOT 3AL cylinder or any other cylinder manufactured from 
aluminum alloy 6351-T6, whether the incident was domestic or foreign, 
to submit the information in their comments to this rulemaking. More 
broadly, we invited commenters to address the issue of whether the new 
inspection requirements proposed in the NPRM should apply to cylinders 
manufactured of aluminum alloy 6351-T6 and used in services other than 
SCUBA, SCBA, or oxygen.

III. Analysis of Comments

    We received comments from several individuals and organizations, 
including cylinder manufacturers, representatives of the SCUBA and 
compressed gas industries, and eddy current test equipment 
manufacturers. In this supplemental notice, we discuss comments 
submitted to the docket, concerns raised by commenters, and our 
decisions on specific issues.

A. Prohibited Use of 6351-T6 Cylinders

    In response to the known susceptibility of cylinders made of 
aluminum alloy 6351-T6 to SLC, the NPRM discussed three possible 
options, which were evaluated as part of a cost-benefit analysis to 
address existing safety concerns: (1) Leaving the cylinder in service 
without taking any additional measures to reduce the risk, (2) 
immediately removing all cylinders made of aluminum alloy 6351-T6 from 
service, or (3) performing a NDE at the time of the cylinder's periodic 
requalification and requiring additional operational controls (OC) 
during the cylinder filling process. After careful analysis, we 
selected the third option.
    Several commenters suggest that option (3) does not provide an 
adequate level of safety. The commenters state that SLC is a 
manufacturing problem, and no level of testing will prevent future 
incidents. These commenters assert that the only way to prevent future 
SLC incidents is to prohibit the use of all aluminum alloy 6351-T6 
cylinders. They also assert that the safety benefits outweigh the costs 
involved in removing these cylinders from service and express concern 
that the SLC problem will only get worse if the cylinders remain in 
service.
    We agree. However, the original economic evaluation showed 
immediate removal of these cylinders from service would place an undue 
economic burden on the affected industries. Although the economic 
burden of immediate removal is not justified, a gradual phase out of 
these cylinders over time will address the safety issue, and limit the 
costs associated with removal of these cylinders. Users of DOT 3AL 
cylinders generally replace them with a new one after 45-50 years. We 
revised the economic analysis to examine the costs of implementing 
option (3) with the addition of a 40-year service life. The economic 
analysis showed the addition of a 40-year service life to option (3) 
would provide an effective phase-out of these cylinders over time 
without imposing significant costs on the affected industries. Since 
most of these cylinders were manufactured prior to 1990, total removal 
of these cylinders would be accomplished by the year 2030. In this 
SNPRM we are proposing the addition of a 40-year service life on 
existing DOT 3AL cylinders manufactured of aluminum alloy 6351-T6. 
Under this proposal, cylinders would be prohibited from service when 
they reach the end of a 40-year service life. We are soliciting 
comments on whether a 40-year period from the date of manufacture is an 
appropriate service life for these affected cylinders.

B. Combined Visual and Eddy Current Testing

    The NPRM proposed the addition of a combined external visual and 
eddy current examination at each required 5-year periodic 
requalification for DOT 3AL cylinders manufactured of aluminum alloy 
6351-T6. The EE would be performed in accordance with the procedure 
outlined in Appendix C to Part 180. The visual examination would be 
conducted in accordance with CGA Pamphlet C-6.1.
    Some commenters express concern over the five-year retest period as 
not frequent enough to detect SLC. One commenter states that experience 
has shown SLC gradually becomes noticeable 2-4 years before a 
catastrophic event. The commenter describes an incident in which a CO 
2 cylinder leaked through the threads during filling. The 
leak was a result of SLC. The cracking was not visible at the previous 
qualification, but in less than a year's time the crack became large 
enough to leak product. Another commenter asserts that cylinders filled 
frequently (e.g., SCUBA) are more susceptible to SLC and should be 
tested more frequently than once every five years. The commenter cites 
the dive industry standard of conducting visual inspections on an 
annual basis and recommends reducing the retest period to 2.5 years.
    We disagree. Research has shown SLC is a slow growing crack. A 
cylinder manufactured of aluminum alloy 6351-T6 properly examined using 
a combination of an external visual and the eddy current is not likely 
to develop a critical SLC within a five year period. Further, requiring 
a more frequent examination would impose an unnecessary burden on the 
regulated community without significantly increasing safety.
    A few commenters express concern about the qualification 
requirements for inspectors who conduct the EEs. A large number of the 
dive and fire industry EEs are conducted by trained technicians that 
have not been specifically approved in accordance with Sec.  107.805 to 
requalify DOT specification cylinders. Commenters suggest it may be 
difficult to locate approved requalifiers with the capability to 
conduct eddy current examinations.
    We recognize it may be difficult to locate an inspector qualified 
to perform

[[Page 61765]]

the EE and specifically approved in accordance with Sec.  107.805. In 
this SNPRM we are proposing to require each cylinder made of aluminum 
alloy 6351-T6 to be initially examined using the eddy current/visual 
examinations within 3 years from publication of a final rule in the 
Federal Register. We believe the transition period provides a 
sufficient amount of time for inspectors to obtain approval to perform 
eddy current/visual examinations in accordance with Sec.  107.805. We 
are soliciting comments on the proposed 3 year transition period for 
initial eddy-current/visual examinations of the affected cylinders.

C. Eddy Current and Visual Examination Method (Part 180, Appendix C)

    Several commenters recommend changes to the EE procedures specified 
in proposed Appendix C to Part 180. Some commenters suggest the 
procedures provided in Appendix C to Part 180 is outdated. They 
recommend revising the language to more appropriately reflect the 
terminology used in the industry today. In addition, some commenters 
suggest the procedure is too specific. One commenter states, ``by 
detailing the exact steps to be followed and describing how the probe 
must be handled, how the defect signal should look, etc., you are in 
essence stating that only one manufacturer's equipment is acceptable 
for the test.'' These commenters note the operational procedures for 
eddy current equipment vary with the manufacturer and test equipment. 
To avoid confusion and conflicting procedures, these commenters 
recommend requiring EEs in accordance with the manufacturer's 
instructions. Some commenters recommend revising Appendix C to Part 180 
to list the elements that must be included in the procedure, and the 
criteria by which cylinders must be condemned, without stating specific 
procedural methods. They suggest this will avoid limiting the industry 
to specific procedures that may conflict with current manufacturer 
recommendations used by industry today. One commenter states it is 
inappropriate for PHMSA to refer to equipment produced by specific 
manufacturers when describing the requirements for an appropriate EE 
and suggest we remove any references to equipment produced by a 
specific manufacturer.
    We agree with the commenters. The procedures proposed in Part 180, 
Appendix C may be too specific. Further, it is not our intention to 
require or endorse the use of eddy current equipment supplied by a 
particular manufacturer. In this SNPRM, we are revising Part 180, 
Appendix C to provide general eddy current and visual examination 
procedures, recordkeeping requirements, and personnel qualifications. 
In addition, we are proposing to require requalifiers to develop, 
update, and maintain examination procedures applicable to the test 
equipment they use to perform eddy current examinations.
    The NPRM proposed that cylinders found to have a two-thread crack 
in the neck or shoulder area must be rejected. Some commenters 
recommend revising the rejection criteria to include any crack in the 
cylinder, rather than any two-thread crack. These commenters suggest 
more stringent rejection criteria will provide a higher level of 
safety.
    We disagree. The rejection criteria stated in the NPRM are based on 
the size of the notch in the standard reference ring used to calibrate 
the eddy current equipment. Aluminum cylinder manufacturers and eddy 
current experts have conducted extensive research to determine the SLC 
rejection criteria. The two-thread length is based on a correlation 
between SLC depth and growth-rate. The SLC initiates from the crown 
(shoulder) and proceeds toward the neck of the cylinder. Research has 
shown existing cracks shorter than two threads are not likely to become 
critical prior to the next requalification (five years).
    The regulations do not currently specify whether the eddy current 
examination should be conducted before, or after the hydrostatic test. 
One commenter requested clarification of this issue. To clarify, the 
eddy current and visual examination may be performed either before or 
after the hydrostatic examination.

D. Training

    The NPRM proposed that in addition to the periodic requalification 
and marking described in Sec.  180.205, cylinders manufactured of 
aluminum alloy 6351-T6 used in SCUBA, SCBA, and oxygen services must be 
subjected to an eddy current and visual examination. The NPRM did not 
propose additional training requirements for persons performing these 
examinations.
    Some commenters express concern that persons performing the 
combination visual and eddy current examination may not receive 
adequate training to perform these tests. These commenters suggest we 
add a formal function-specific training requirement for persons 
performing these examinations.
    We agree with the commenters. In this SNPRM, we are proposing 
additional training requirements in Part 180, Appendix C for persons 
who perform EEs combined with visual examinations of DOT 3AL cylinders 
manufactured of aluminum alloy 6351-T6. We are soliciting comments on 
the proposed training requirements.

E. CO2 Service

    The requalification method proposed in the NPRM for aluminum 
cylinders constructed of 6351-T6 aluminum alloy would have applied only 
to cylinders used in SCUBA, SCBA, and oxygen service. We did not 
propose to require cylinders used in CO2 service to be 
subjected to the visual and eddy current examination.
    One commenter expresses concern that the proposed revision to the 
requalfication method for aluminum alloy cylinders does not include 
cylinders used in CO2 service. The commenter states, ``It is 
true that CO2 beverage cylinders are typically filled to 
lower pressures than those used in SCUBA, SCBA and oxygen services. 
However, the incidence of SLC is great enough that we believe it 
compromises safety to exclude any cylinders from the proposed rule.'' 
Another commenter conducted an in-house survey of condemned cylinders 
over a three year period (2001-2003). The results of the survey showed 
a significant number of CO2 cylinders condemned due to SLC.
    We agree with commenters that aluminum cylinders used in 
CO2 service are susceptible to SLC. In this SNPRM, we 
propose to expand the scope of the rulemaking to include CO2 
cylinders. Many users of aluminum alloy cylinders in the beverage 
service industry are already conducting EEs. We believe including 
CO2 cylinders will further enhance transportation safety.

F. Operational Controls for Filling Aluminum Alloy Cylinders

    In the NPRM, we proposed to add operational controls during the 
filling of cylinders constructed of aluminum alloy 6351-T6. The 
proposed operational controls included a provision requiring the 
cylinder filler to allow only those individuals essential to the 
filling process to be in the vicinity of the cylinder during the 
filling process.
    Commenters generally support this requirement. One commenter 
suggests the term ``vicinity'' is not clearly defined and could lead to 
wide interpretation. The commenter requests we clarify the area that is 
intended to be covered by the term ``vicinity.''

[[Page 61766]]

    We recognize the term vicinity could be widely interpreted. The 
intent of this requirement is to protect non-essential personnel and 
innocent bystanders from injury if a cylinder were to rupture during 
filling. For purposes of this requirement, vicinity means a location 
near or around the filling operation that would impose an unreasonable 
risk of injury to an individual if the cylinder were to rupture during 
the filling process. The actual distance could vary broadly depending 
upon the type of safety mechanisms in place and the actual square 
footage of a particular filling location.

IV. Proposals in This SNPRM

    In this SNPRM, we are revising certain amendments originally 
proposed in the NPRM, expanding the scope of the rulemaking, and 
proposing additional requirements for DOT 3AL cylinders manufactured of 
aluminum alloy 6351-T6. Proposed amendments include:
     Expanded requalification and use requirements to include 
DOT 3AL cylinders manufactured of aluminum alloy 6351-T6 used in 
CO2 service.
     A 40-year service life for cylinders manufactured of 
aluminum alloy 6351-T6 and used in SCBA, SCUBA, oxygen and 
CO2 service.
     Additional training requirements for persons performing 
the eddy current examination combined with a visual inspection.
     Modified procedures and recordkeeping requirements for 
EEs.
     A requirement to perform the initial eddy current 
examination combined with visual inspection for DOT 3AL cylinders 
manufactured of aluminum alloy 6351-T6 within three years of 
publication of a final rule in the Federal Register.

V. Section-by-Section Review

Part 173

Section 173.301
    We are proposing to revise paragraph (d) and add a new paragraph 
(o) to impose a 40-year service life on cylinders manufactured of 
aluminum alloy 6351-T6 and used in SCBA, SCUBA, oxygen and 
CO2 service. The 40-year service life will promote safety by 
phasing out the use of cylinders susceptible to SLC.
Section 173.302
    We are proposing to add a new paragraph (e) to require that 
operational controls must be in place during the filling process for 
cylinders manufactured of aluminum alloy 6351-T6. The operational 
controls will reduce the risk of injury and property damage during the 
filling process.

Part 180

Section 180.205
    We are proposing to revise paragraph (f)(4) to provide reference to 
Part 180, Appendix C for requalification requirements for DOT 3AL 
cylinders manufactured of aluminum alloy 6351-T6.
Section 180.209
    We are proposing to amend paragraph (a), the entry for the DOT 3AL 
cylinder in the ``Requalification of Cylinders'' table to add a 
reference to the new paragraph (m). In addition, we propose to add a 
new paragraph (m) to include a NDE for cylinders manufactured of 
aluminum alloy 6351-T6. The NDE will be used to detect SLC in the neck 
and shoulder area of the cylinder. The initial NDE would be required 
within three years following publication of a final rule in the Federal 
Register, and every five years thereafter.
Section 180.213
    We are revising paragraph (d) and adding a new paragraph (f)(8) to 
specify the requalification marking requirements for aluminum cylinders 
successfully passing the combined eddy current examination and visual 
inspection. We are soliciting comments on whether ``VE'' is a suitable 
marking designation for cylinders passing the examination.
Appendix C to Part 180
    We are proposing to amend Appendix C to Part 180 to provide 
acceptable procedures, training and recordkeeping requirements for 
performing the eddy current examination and visual inspection of 
cylinders manufactured of aluminum alloy 6351-T6.

VI. Regulatory Analyses and Notices

A. Statutory/Legal Authority for This Rulemaking

    This SNPRM 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 material in intrastate, interstate, 
and foreign commerce. To this end, as discussed in detail earlier in 
this preamble, the SNPRM proposes to revise current HMR requirements 
applicable to aluminum cylinders manufactured using aluminum alloy 
6351-T6. The purpose of the SNPRM is to adopt a standard for early 
detection of SLC to reduce the risk of a cylinder rupture and to 
establish a service life for cylinders manufactured of aluminum alloy 
6351-T6.

B. Executive Order 12866 and DOT Regulatory Policies and Procedures

    This proposed rule is not considered a significant regulatory 
action under section 3(f) of Executive Order 12866 and, therefore, was 
not reviewed by the Office of Management and Budget. The proposed rule 
is not considered a significant rule under the Regulatory Policies and 
Procedures of the Department of Transportation [44 FR 11034].
    The compliance costs associated with this rule are minimal. The 
regulatory analysis indicates the increased cost for imposing a 40-year 
service life, performing an NDE, and implementing operational controls 
is small compared to the cost and safety risks of doing nothing; it is 
significantly less than the cost of immediately removing all cylinders 
from service. The annual benefits of implementing the proposals in this 
NPRM total $1,123,969 for avoided injuries and fatalities compared to 
an annual cost to the industry of $669,130. The economic evaluation 
data were based on information obtained from cylinder manufacturers, 
industrial gas companies, cylinder inspectors, and on metallurgical 
evaluation of the ruptured cylinders. A regulatory analysis is 
available for review in the docket.

C. Executive Order 13132

    This proposed rule has been analyzed in accordance with the 
principles and criteria contained in Executive Order 13132 
(``Federalism''). This proposed rule would preempt State, local and 
Indian tribe requirements but does not adopt any regulation with 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 
hazmat 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 certain covered subjects. Covered subjects are:
    (1) The designation, description, and classification of hazardous 
material;
    (2) The packing, repacking, handling, labeling, marking, and 
placarding of hazardous material;
    (3) The preparation, execution, and use of shipping documents 
related to

[[Page 61767]]

hazardous material 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; and
    (5) The design, manufacturing, fabricating, marking, maintenance, 
reconditioning, repairing, or testing of a packaging or container 
represented, marked, certified, or sold as qualified for use in 
transporting hazardous material.
    This proposed rule covers items 2 and 5 and would preempt any 
State, local, or Indian tribe requirements not meeting the 
``substantively the same'' standard.
    Pursuant to Sec.  5125(b)(2) of the Federal hazmat law, if the 
Secretary of Transportation issues a regulation concerning any of the 
covered subjects, the Secretary 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 final rule and not later than two years after the 
date of issuance. PHMSA has determined the effective date of Federal 
preemption for these requirements will be one year from the date of 
publication of a final rule in the Federal Register.

D. Executive Order 13175

    This proposed rule 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, does not 
impose substantial direct compliance costs, and is not required by 
statute, the funding and consultation requirements of Executive Order 
13175 do not apply.

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

    The Regulatory Flexibility Act (5 U.S.C. 601 et seq.) requires an 
agency to review regulations to assess their impact on small entities 
unless the agency determines a rule is not expected to have a 
significant economic impact on a substantial number of small entities. 
This rule imposes only minimal new costs of compliance on the regulated 
industry. Based on the assessment in the regulatory evaluation, I 
hereby certify that while this rule applies to a substantial number of 
small entities, there will not be a significant economic impact on 
those small entities. A detailed Regulatory Flexibility analysis is 
available for review in the docket.
    This proposed rule has been developed in accordance with Executive 
Order 13272 (``Proper Consideration of Small Entities in Agency 
Rulemaking'') and DOT's policies and procedures to promote compliance 
with the Regulatory Flexibility Act to ensure potential impacts of 
draft rules on small entities are properly considered.

F. Paperwork Reduction Act

    PHMSA currently has an approved information collection under OMB 
Control No. 2137-0022, Testing, Inspection, and Marking Requirements 
for Cylinders'' with 168,431 burden hours, and an expiration date of 
August 31, 2008. This supplemental notice of proposed rulemaking may 
result in a modest increase in annual burden and costs based on a new 
information collection requirement. These proposals regarding the 
shipment of aluminum cylinders may result in a new information 
collection requirement will be submitted to OMB for review and 
approval.
    Section 1320.8(d), Title 5, Code of Federal Regulations requires 
PHMSA to provide interested members of the public and affected agencies 
an opportunity to comment on information collection and recordkeeping 
requests. This notice identifies a new information collection request 
PHMSA will submit to OMB for approval based on the requirements in this 
supplemental proposed rulemaking.
    PHMSA has developed burden estimates to reflect changes in this 
SNPRM. PHMSA estimates the total information collection and 
recordkeeping burden as proposed would be as follows:
    OMB No. 2137-0022:
    Total Annual Number of Responders: 139,352.
    Total Annual Responses: 153,287.
    Total Annual Burden Hours: 271,461.
    Total Annual Burden Cost: $2,615,515.
    Total One-Time Start-Up Cost: $964,000.
    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.
    Address written comments to the Dockets Unit as identified in the 
ADDRESSES section of this rulemaking. We must receive your comments 
prior to the close of comment period identified in the DATES section of 
this rulemaking. Under the Paperwork Reduction Act of 1995, no person 
is required to respond to an information collection unless it displays 
a valid OMB control number. If these proposed requirements are adopted 
in a final rule, PHMSA will submit the revised information collection 
and recordkeeping requirements to the Office of Management and Budget 
for approval.
    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, Room 8430, 400 Seventh Street, SW., Washington, DC 
20590-0001, Telephone (202) 366-8553. We will publish a notice advising 
interested parties of the OMB approval for this information collection 
request when approved by OMB.
    In addition, you may submit comments specifically related to the 
information collection burden to the PHMSA Desk Officer, OMB, at fax 
number 202-395-6974. Under the Paperwork Reduction Act of 1995, no 
person is required to respond to an information collection unless it 
displays a valid OMB control number.

G. Regulation Identifier Number (RIN)

    A regulation identifier number (RIN) is assigned to each regulatory 
action listed in the Unified Agenda of Federal Regulations. The 
Regulatory Information Service Center publishes the Unified Agenda in 
April and October of each year. The RIN number contained in the heading 
of this document can be used to cross-reference this action with the 
Unified Agenda.

H. Unfunded Mandates Reform Act

    This proposed rule does not impose unfunded mandates under the 
Unfunded Mandates Reform Act of 1995. It does not result in costs of 
$120.7 million or more to either State, local or tribal governments, in 
the aggregate, or to the private sector, and is the least burdensome 
alternative that achieves the objective of the rule.

I. Environmental Assessment

    The National Environmental Policy Act of 1969 (NEPA), as amended 
(42 U.S.C. 4321-4347), requires Federal agencies to consider the 
consequences of major federal actions and prepare a detailed statement 
on actions significantly affecting the quality of the human 
environment. There are no significant environmental impacts associated 
with this proposed rule. PHMSA is amending requirements in the HMR 
pertaining to DOT 3AL aluminum cylinders. The purpose of this 
rulemaking initiative is to minimize personal injury during the 
cylinder

[[Page 61768]]

filling process and to adopt a standard for early detection of 
sustained load cracking in order to reduce the risk of a cylinder 
rupture. Adopting a standard for early detection of sustained load 
cracking in order to reduce the risk of a cylinder rupture has no 
potential for environmental damage or contamination.

J. Privacy Act

    Anyone is able to search the electronic form of all comments 
received into any of our dockets by the name of the individual 
submitting the comment (or signing the comment, 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) or you may visit 
https://dms.dot.gov.

List of Subjects

49 CFR Part 173

    Hazardous materials transportation, Incorporation by reference, 
Packaging and containers, Radioactive materials, Reporting and 
recordkeeping requirements, Uranium.

49 CFR Part 180

    Hazardous materials transportation, Incorporation by reference, 
Motor vehicle safety, Packaging and containers, Reporting and 
recordkeeping requirements.

    In consideration of the foregoing, we propose to amend 49 CFR 
chapter I, subchapter C as follows:

PART 173--SHIPPERS--GENERAL REQUIREMENTS FOR SHIPMENT AND PACKAGES

    1. The authority citation for part 173 continues to read as 
follows:

    Authority: 49 U.S.C. 5101-5127, 44701; 49 CFR 1.45, 1.53.

    2. In Sec.  173.301, paragraph (d) is revised and a new paragraph 
(o) is added to read as follows:


Sec.  173.301  General requirements for shipment of compressed gases in 
cylinders and spherical vessels.

* * * * *
    (d) Gases capable of combining chemically. A filled cylinder may 
not contain any gas or material capable of combining chemically with 
the cylinder's contents or with the cylinder's material of 
construction, so as to endanger the cylinder's serviceability.
* * * * *
    (o) DOT 3AL cylinders made of aluminum alloy 6351-T6. A DOT 3AL 
cylinder manufactured of aluminum alloy 6351-T6 and used in self-
contained underwater breathing apparatus (SCUBA), self-contained 
breathing apparatus (SCBA), oxygen, or CO\2\ services has a 40-year 
service life from the date of manufacture. No person may fill and offer 
for transportation or transport a DOT 3AL cylinder made of aluminum 
alloy 6351-T6 that has been in service longer than forty years. 
However, a cylinder in transportation or a cylinder filled prior to the 
expiration of its authorized service life may be transported for 
reprocessing or disposal of the cylinder's contents. A DOT 3AL cylinder 
manufactured of aluminum alloy 6351-T6 may not be filled and offered 
for transportation or transported with pyrophoric gases.
    3. In Sec.  173.302, a new paragraph (e) is added to read as 
follows:


Sec.  173.302  Filling of cylinders with nonliquefied (permanent) 
compressed gases.

* * * * *
    (e) DOT 3AL cylinders manufactured of 6351-T6 aluminum alloy. 
Suitable safeguards should be provided to protect personnel and 
facilities should failure occur while filling cylinders manufactured of 
aluminum alloy 6351-T6 used in self-contained underwater breathing 
apparatus (SCUBA), self-contained breathing apparatus (SCBA), oxygen 
and Carbon dioxide services. The cylinder filler should allow only 
those individuals essential to the filling process to be in the 
vicinity of the cylinder during the filling process.

PART 180--CONTINUING QUALIFICATION AND MAINTENANCE OF PACKAGINGS

    4. The authority citation for part 180 continues to read as 
follows:

    Authority: 49 U.S.C. 5101-5127; 49 CFR 1.53.

    5. In Sec.  180.205, paragraph (f)(4) is revised to read as 
follows:


Sec.  180.205  General requirements for requalification of cylinders.

* * * * *
    (f) * * *
    (4) In addition to other requirements prescribed in this paragraph 
(f), a specification cylinder made of aluminum alloy 6351-T6 must be 
inspected for sustained load cracking in accordance with Appendix C of 
this part.
* * * * *
    6. In Sec.  180.209, in paragraph (a), in the ``Requalification of 
Cylinders'' table the entry ``DOT 3AL'' is revised, and a new paragraph 
(m) is added to read as follows:


Sec.  180.209  Requirements for requalification of specification 
cylinders.

* * * * *
    (a) * * *

               Table 1.--Requalification of Cylinders \1\
------------------------------------------------------------------------
  Specification under which       Minimum test         Requalification
      cylinder was made       pressure (psig.) \2\     period (years)
------------------------------------------------------------------------
 
                              * * * * * * *
DOT 3AL.....................  5/3 times service     5 or 12 (see Sec.
                               pressure.             180.209(j) and Sec.
                                                       180.209(m) \3\).
 
                             * * * * * * *
------------------------------------------------------------------------
\1\ Any cylinder not exceeding 2 inches outside diameter and less than 2
  feet in length is excepted from volumetric expansion test.
\2\ For cylinders not marked with a service pressure, see Sec.
  173.301(e)(1) of this subchapter.
\3\ This provision does not apply to aluminum cylinders used in fire
  extinguisher service.

* * * * *
    (m) DOT-3AL cylinders manufactured of 6351-T6 aluminum alloy. In 
addition to the periodic requalification and marking described in Sec.  
180.205, each cylinder manufactured of aluminum alloy 6351-T6 used as a 
self-contained underwater breathing apparatus (SCUBA), a self-contained 
breathing apparatus (SCBA), or in oxygen or Carbon dioxide service must 
be requalified and inspected for sustained load cracking in accordance 
with the non-destructive examination method described in the following 
table. Each cylinder with sustained load cracking that has expanded 
into the neck threads must be condemned in accordance with

[[Page 61769]]

Sec.  180.205(i). This provision does not apply to aluminum cylinders 
used in fire extinguisher service or industrial gases in other than 
Carbon dioxide service.

               Requalification and Inspection of DOT-3AL Cylinders Made of Aluminum Alloy 6351-T6
----------------------------------------------------------------------------------------------------------------
                                                                                                Requalification
     Requalification requirement         Examination procedure \1\    Sustained load cracking    period (years)
                                                                       rejection criteria \2\         \3\
----------------------------------------------------------------------------------------------------------------
Eddy current examination combined      In accordance with Appendix C  Any 2-thread crack in                   5
 with visual inspection.                of this part. Visual           the neck or shoulder
                                        inspection--In accordance      area.
                                        with CGA Pamphlet C-6.1
                                        (IBR; see Sec.   171.7 of
                                        this subchapter).
----------------------------------------------------------------------------------------------------------------
\1\ The requalifier performing eddy current must be familiar with the eddy current equipment and must
  standardize (calibrate) the system in accordance with the requirements provided in Appendix C to this part.
\2\ The eddy current must be applied from the inside of the cylinder's neck to detect any sustained load
  cracking that has expanded into the neck threads.
\3\ Each cylinder must receive an initial inspection using the eddy current examination combined with visual
  inspection prior to [DATE THREE YEARS FOLLOWING THE PUBLICATION DATE OF THE FINAL RULE IN THE Federal
  Register] and every 5 years thereafter.

    7. In Sec.  180.213, paragraph (d) introductory text is revised and 
a new paragraph (f)(8) is added to read as follows:


Sec.  180.213  Requalification markings.

* * * * *
    (d) Requalification markings. Each cylinder that has successfully 
passed requalification must be marked with the RIN set in a square 
pattern, between the month and year of the requalification date. The 
first character of the RIN must appear in the upper left corner of the 
square pattern; the second in the upper right; the third in the lower 
right; and the fourth in the lower left. Example: A cylinder 
requalified in September 1998, and approved by a person who has been 
issued RIN ``A123'', would be marked plainly and permanently into the 
metal of the cylinder in accordance with location requirements of the 
cylinder specification or on a metal plate permanently secured to the 
cylinder in accordance with paragraph (b) of this section. An example 
of the markings prescribed in this paragraph (d) is as follows:

                                   A1
                                  9 98 X
                                   32
 

Where:

``9'' is the month of requalification
``A123'' is the RIN
``98'' is the year of requalification, and
``X'' represents the symbols described in paragraphs (f)(2) through 
(f)(8) of this section.
* * * * *
    (f) * * *
    (8) For designation of the eddy current examination combined with a 
visual inspection, the marking is as illustrated in paragraph (d) of 
this section, except that the ``X'' is replaced with the letters 
``VE.''
    8. In Part 180, Appendix C is added to read as follows:

Appendix C to Part 180--Eddy Current Examination With Visual Inspection 
for DOT-3AL Cylinders Manufactured of Aluminum Alloy 6351-T6

    1. Examination Procedure. Each facility that performs eddy 
current examination with visual inspection must develop, update, and 
maintain a written examination procedure applicable to the test 
equipment it uses to perform eddy current examinations.
    2. Visual examinations. Visual examinations of the neck and 
shoulder area of the cylinder must be conducted before and after the 
eddy current examination and in accordance with CGA pamphlet C-6.1 
(IBR; see Sec.  171.7 of this subchapter).
    3. Eddy Current Equipment. A reference ring and probe for each 
DOT-3AL cylinder manufactured of aluminum alloy 6351-T6 to be 
inspected must be available at the examination facility. Eddy 
current equipment must be capable of accurately detecting the 
notches on the standard reference ring.
    4. Eddy Current Reference Ring. The reference ring must be 
produced to represent the outer diameter (O.D.) of each cylinder to 
be tested. The reference ring must include artificial notches that 
will simulate a neck crack. The size of the artificial notch (depth 
and length) must have a depth equal to \1/3\ of the wall thickness 
of the neck and a length equal to two threads. The standard 
reference must have a drawing that includes the diameter of the 
ring, and depth and length of each notch.
    5. Rejection Criteria. A cylinder must be rejected if the eddy 
current examination reveals any crack in the neck of 2 thread 
lengths or more.
    6. Examination equipment records.
    Records of eddy current inspection shall contain the following 
information:
    (i) Equipment manufacturer, model number and serial number.
    (ii) Probe description and unique identification (e.g., serial 
number, part number, etc.).
    7. Eddy current examination reporting and record retention 
requirements. Daily records of eddy current examinations must be 
maintained by the person who performs the requalification until 
either the expiration of the requalification period or until the 
cylinder is again requalified, whichever occurs first. These records 
must be made available for inspection by a representative of the 
Department on request. Eddy current examination records shall 
contain the following information:
    (i) Specification of each standard reference ring used to 
perform the eddy current examination.
    (ii) DOT specification or exemption number of the cylinder, 
manufacturer's name or symbol, owner's name or symbol, and date of 
manufacture.
    (iii) Name of test operator performing the eddy current 
examination.
    (iv) Date of eddy current examination.
    (v) Location and type of defect on the cylinder crown or the 
threaded neck (e.g., 5 threads).
    (vi) Acceptance/rejection results (e.g. pass or fail).
    (vii) Retester identification number.
    8. Personnel Qualification Requirements. Each person who 
performs eddy current and visual examinations, and evaluates and 
certifies retest results must satisfy one of the following 
qualification requirements:
    (i) Is certified to a minimum Level I in accordance with the 
American Society for Nondestructive Testing (ASNT) Recommended 
Practice SNT-TC-1A; or
    (ii) Has received a certification by the employer or the eddy 
current equipment manufacturer that he/she has been trained and 
tested in the eddy current and visual examination procedures.
    9. Training Records. A record of current training must be 
maintained for each employee who performs eddy current and visual 
examinations in accordance with Sec.  172.704(d).

    Issued in Washington, DC on October 17, 2005, under authority 
delegated in 49 CFR parts 1.45 and 1.53.
Robert A. McGuire,
Associate Administration for Hazardous Materials Safety.

[FR Doc. 05-21273 Filed 10-25-05; 8:45 am]
BILLING CODE 4910-60-P