[Federal Register Volume 89, Number 110 (Thursday, June 6, 2024)]
[Notices]
[Pages 48482-48484]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2024-12395]


=======================================================================
-----------------------------------------------------------------------

DEPARTMENT OF TRANSPORTATION

Pipeline and Hazardous Materials Safety Administration

[Docket No. PHMSA-2023-0130 (Notice No. 2024-06)]


Hazardous Materials: Request for Feedback on Tare Weight Marking 
Policy for Cylinders

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

ACTION: Notice; request for information.

-----------------------------------------------------------------------

SUMMARY: The Pipeline and Hazardous Materials Safety Administration 
(PHMSA) is publishing this notice to solicit information pertaining to 
the current tare weight, mass weight, and water capacity marking 
requirements for compressed gas cylinders.

DATES: Interested parties are invited to submit comments on or before 
September 4, 2024. Comments received after that date will be considered 
to the extent possible.

ADDRESSES: You may submit comments identified by the Docket Number 
PHMSA-2023-0130 by any of the following methods:
     Federal eRulemaking Portal: http://www.regulations.gov. 
Follow the instructions for submitting comments.
     Fax: 1-202-493-2251.
     Mail: Docket Management System; 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: Docket Management System; 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 (PHMSA-2023-0130) for this notice. To avoid duplication, 
please use only one of these four methods. All comments received will 
be posted without change to the Federal Docket Management System (FDMS) 
and will include any personal information you provide.
    Docket: For access to the dockets to read background documents or 
comments received, go to http://www.regulations.gov or the Department 
of Transportation's (DOT) Docket Operations Office (see ADDRESSES).
    Privacy Act: In accordance with 5 U.S.C. 553(c), DOT solicits 
comments from the public. DOT posts these comments, without edit, 
including any personal information the commenter provides, to http://www.regulations.gov, as described in the system of records notice (DOT/
ALL-14 FDMS), which can be reviewed at http://www.dot.gov/privacy.
    Confidential Business Information (CBI): CBI is commercial or 
financial information that is both customarily and actually treated as 
private by its owner. Under the Freedom of Information Act (FOIA) (5 
U.S.C. 552), CBI is exempt from public disclosure. If your comments 
responsive to this notice contain commercial or financial information 
that is customarily treated as private, that you actually treat as 
private, and that is relevant or responsive to this notice, it is 
important that you clearly designate the submitted comments as ``CBI.'' 
Please mark each page of your submission containing CBI as ``PROPIN.'' 
Submissions containing CBI should be sent to Steven Andrews, Standards 
and Rulemaking Division, 202-366-8553, Pipeline and Hazardous Materials 
Safety Administration, U.S. Department of Transportation, 1200 New 
Jersey Avenue SE, Washington, DC 20590-0001. Any commentary PHMSA 
receives that is not specifically designated as CBI will be placed in 
the public docket for this notice.

FOR FURTHER INFORMATION CONTACT: Noah Jacobson by email at 
[email protected], or Steven Andrews by email at 
[email protected] or by phone at 202-366-8553.

SUPPLEMENTARY INFORMATION:

I. Purpose

    PHMSA is publishing this notice to solicit input pertaining to the 
current tare weight marking requirements in the Hazardous Materials 
Regulations (HMR; 49 CFR parts 171-180)--specifically, Sec.  
178.35(f)(8)--regarding DOT specification 4B, 4BA, 4BW, and 4E 
cylinders used in liquefied compressed gas service to determine what, 
if any, effect they may have on the safe transportation of hazardous 
materials.

II. Background

    On May 1, 2009, the Compressed Gas Association (CGA) petitioned (P-
1540 \1\) PHMSA to revise Sec.  178.35(f) to require DOT 4B, 4BA, 4BW, 
and 4E cylinders be marked with the tare weight or mass weight, and 
water capacity. Tare weight is the weight of the fully assembled 
cylinder, including the valve(s) and other permanently affixed 
appurtenances; mass weight is the weight of the fully assembled 
cylinder, excluding valve(s) and removable protective cap(s) or 
cover(s); and water capacity is the total volume of water the cylinder 
is capable of holding. The purpose of marking these measurements on the 
cylinder is to ensure that cylinders filled by weight, a method 
primarily used for liquefied gases like propane, are filled with the 
correct amount of material. The HMR requires that, for liquefied gases, 
the content of the cylinder be checked after filling by an ``accurate 
scale''--see Sec.  173.304a(c)--to avoid overfilling cylinders, which 
can cause cylinder rupture.
---------------------------------------------------------------------------

    \1\ P-1540--CGA (PHMSA-2009-0146), https://www.regulations.gov/document/PHMSA-2009-0146.
---------------------------------------------------------------------------

    The CGA's petition requested that the markings be permitted to vary 
from the actual tare weight, mass weight, and water capacity of the 
cylinder to account for the accuracy of the stamped weight during 
manufacture. Specifically, the CGA's petition requested that for 
cylinders up to and including 25 pounds, the tare weight/mass weight 
marking be allowed a lower tolerance of three (3) percent and an upper 
tolerance of one (1) percent, while the tare weight/mass weight marking 
for cylinders larger than 25 pounds be allowed a lower tolerance of two 
(2) percent and an upper tolerance of one (1) percent. Similarly, the 
CGA's petition requested that water capacity tolerances for cylinders 
up to and including 25 pounds of -1 percent with no requirement for an 
upper tolerance, and for cylinders larger than 25 pounds of minus -0.5 
percent with no requirement for an upper tolerance. In

[[Page 48483]]

practice, a three (3) percent tolerance in the lower bound equates to 
approximately 0.5 pound for typical consumer-sized propane cylinders 
with average stamped/stenciled tare weights between 16.6 pounds and 18 
pounds (i.e., a cylinder with a true tare weight of 17 pounds could be 
marked as low as 16.5 pounds).\2\
---------------------------------------------------------------------------

    \2\ Calculation: 17 * .03 = .51. 17-.51 = 16.49 rounded to 16.5.
---------------------------------------------------------------------------

    The CGA's petition was accepted on July 23, 2009, and first 
addressed in the HM-234 Advanced Notice of Proposed Rulemaking (ANPRM) 
\3\ titled ``Hazardous Materials; Miscellaneous Amendments Pertaining 
to DOT Specification Cylinders (RRR).'' In the ANPRM, PHMSA solicited 
data from the regulated community regarding the costs, benefits, and 
implications of the proposed cylinder markings on manufacturers, as 
detailed in the CGA's petition. PHMSA also sought data on alternative 
strategies to prevent overfilling accidents, as well as the safety 
advantages of the proposed markings. The goal of the ANPRM was to 
collect industry information to assess whether the proposed enhanced 
cylinder markings would offer safety benefits that justify the 
potential costs, particularly for small businesses.
---------------------------------------------------------------------------

    \3\ 77 FR 31551 (May 29, 2012).
---------------------------------------------------------------------------

    In response to the ANPRM, commenters voiced concerns that mandating 
both tare weight and mass weight markings could lead to confusion among 
cylinder fillers due to potential discrepancies between the 
manufactured stamped weights. The commenters suggested that PHMSA 
refine the regulatory language to assign the marking of the tare weight 
specifically to the valve installer, given that some cylinders are not 
valved by the original manufacturer. The commenters also pointed out 
the limited space available for additional stamping on some cylinders 
that could affect the space for retest information. In summary, the 
commenters urged careful consideration of the language to prevent 
conflicting stamped weights, and to ensure the party best suited to 
mark the tare weight is clearly identified.
    PHMSA then published the HM-234 NPRM \4\ titled ``Hazardous 
Materials; Miscellaneous Amendments Pertaining to DOT Specification 
Cylinders (RRR),'' which proposed to revise Sec.  178.35(f) to require 
marking the tare weight or mass weight, in addition to the water 
capacity, on DOT 4B, 4BA, 4BW, and 4E cylinders. The NPRM proposed to 
adopt the accuracy tolerances as presented in CGA's petition. PHMSA 
emphasized that while cylinder markings are crucial for safely filling 
liquefied compressed gas, they cannot replace comprehensive personnel 
training and procedures. These measures, along with ongoing 
requalification and maintenance of cylinders, are essential for 
preventing incidents. PHMSA subsequently expressed interest in 
receiving further comments on the possibility of extending this marking 
requirement to other DOT-specification cylinders, and was particularly 
interested in understanding the associated costs, benefits, and safety 
implications.
---------------------------------------------------------------------------

    \4\ 81 FR 48978 (July 26, 2016).
---------------------------------------------------------------------------

    In response to the NPRM, PHMSA received comments opposing the 
proposed requirement to mark all DOT 4B, 4BA, 4BW, and 4E cylinders 
with tare weight or mass weight, and water capacity. These commenters 
cited concerns about the challenges and costs of implementing the 
proposal. In particular, commenters noted that while many DOT 4B, 4BA, 
4BW, and 4E cylinders are used for liquefied gases, some are used in 
non-liquefied gas services, such as fire extinguishers, and these 
markings do not serve a useful purpose for a cylinder filled by 
pressure. Other commenters were generally supportive of the proposed 
revisions and reflected a range of perspectives on the costs, benefits, 
and potential unintended consequences of the proposed marking 
requirements. PHMSA received no comments related to existing tare-
weight marking standards for consumer cylinders mandated by states.
    PHMSA then published the HM-234 final rule \5\ to revise certain 
requirements applicable to the manufacture, use, and requalification of 
DOT 4B, 4BA, 4BW, and 4E cylinders. Prior to this revision in the HM-
234 final rule, the HMR did not contain any requirement for liquefied 
compressed gas cylinders that are filled by weight to be marked with a 
tare weight, mass weight, or water capacity. PHMSA determined that 
these cylinder measurements are critical for liquefied compressed 
gases, which are filled by weight, rather than by pressure. Improperly 
filled liquefied gas cylinders (i.e., overfilled cylinders) have 
contributed to significant hazardous materials incidents, including the 
2014 Philadelphia, Pennsylvania, food truck explosion.\6\ The HM-234 
final rule revised the NPRM's proposal and imposed the tare weight or 
mass weight, and water capacity marking requirements to only apply to 
DOT 4B, 4BA, 4BW, and 4E cylinders used for liquefied compressed gases, 
an adjustment made in response to the comments in the NPRM. PHMSA 
received no comments regarding the accuracy tolerances proposed in the 
NPRM, and the final rule adopted them as proposed.
---------------------------------------------------------------------------

    \5\ 85 FR 85380 (Dec. 28, 2020).
    \6\ https://www.nafi.org/blog/propane-safety-investigation-findings-and-lessons-learned-in-the-2014-philadelphia-food-truck-explosion/.
---------------------------------------------------------------------------

    On January 23, 2023, PHMSA received a petition for rulemaking (P-
1772) \7\ from the National Council on Weights and Measurements (NCWM) 
requesting that PHMSA reconsider the allowable differences on stamped 
tare weight verses actual tare weight for liquefied petroleum gas (LPG) 
cylinders. In their petition, NCWM recommends a 0.5 percent 
tolerance between actual and marked TW/MW for cylinders weighing 25 
pounds or less, with an additional requirement that ``good quality 
control practices'' be followed. This tolerance is significantly 
tighter than the accuracy tolerances adopted in the HM-234 final rule 
(i.e., 6x less variance is permitted in the tare weight/mass weight 
marking for a cylinder weighing less than 25 pounds).
---------------------------------------------------------------------------

    \7\ P-1772--National Council on Weights and Measurements, 
https://www.regulations.gov/docket/PHMSA-2023-0008/document.
---------------------------------------------------------------------------

    The NCWM also suggested that the stamped tare weight on ``used'' 
cylinders be verified periodically to ensure accuracy. Additionally, 
the NCWM recommends that the allowable difference between the stamped 
tare weight verses the actual tare weight for cylinders more than 25 
pounds be reviewed and be based on data. Finally, the NCWM suggests 
that the current edition of the National Institute of Standards and 
Technology (NIST) Handbook 44 \8\ be incorporated by reference for the 
marking and weighing of cylinders to be filled with liquefied petroleum 
gas. NCWM also requests that PHMSA add an ``Average Requirement'' to 
the tare weight regulations to improve measurement accuracy and 
production controls, and to ensure a business is not using the 
allowable differences to gain a competitive advantage. The NCWM 
proposes the ``average requirement'' to mean ``when used to determine 
the net contents of cylinders, the stamped or stenciled tare weights of 
cylinders at a single place of business found to be in error 
predominantly in a direction favorable to the seller and near the 
allowable difference limit shall be considered to be ``not in 
conformance with these requirements.''
---------------------------------------------------------------------------

    \8\ National Institute of Standards and Technology (NIST) 
Handbook 44, https://www.nist.gov/pml/owm/nist-handbook-44-current-edition.
---------------------------------------------------------------------------

    PHMSA requests feedback from the public on the current regulation 
as

[[Page 48484]]

adopted in the HM-234 final rule, and on the proposed provisions in the 
NCWM petition.

III. PHMSA's Current Tare Weight Marking Requirement for Cylinders

    The HMR mandates in Sec.  178.35(f) that DOT 4B, 4BA, 4BW, and 4E 
cylinders--used for liquefied compressed gases--be marked with either 
tare weight or mass weight, in addition to the water capacity. For 
cylinders weighing 25 pounds or less at the time of manufacture, a 
variance is permitted with a lower tolerance of three (3) percent and 
an upper tolerance of one (1) percent. For cylinders weighing more than 
25 pounds at the time of manufacture, a variance is allowed with a 
lower tolerance of two (2) percent and an upper tolerance of one (1) 
percent. If mass weight marking is chosen over tare weight marking, the 
same variance tolerances apply based on whether the manufacturing mass 
exceeds or is at or under 25 pounds.

IV. Request for Feedback

    PHMSA requests comment on the following questions to better inform 
potential regulatory revisions. For all questions, please explain your 
answers and provide any economic, technical, or other information 
available to you as justification for your response:
    1. Do you believe the current language for the marking of DOT 
cylinders in Sec.  178.35(f)(8) leads to confusion between marked tare 
weight at the time of manufacture and the stamped tare weight for the 
filling of cylinders?
    2. How should PHMSA revise the requirements in Sec.  178.35(f)(8) 
for marking of tare weights on DOT 4B, 4BA, 4BW, and 4E cylinders used 
in liquefied compressed gas service?
    3. What impact would PHMSA incorporating the current edition of 
NIST Handbook 44 for scales used to weigh cylinders containing 
liquefied compressed gases have on ensuring accurate scales in both 
direct sale applications and for prepackaging liquefied compressed gas 
cylinders in advance of sale?
    4. What would be the impacts of PHMSA adding an ``average 
requirement'' to the tare weight regulations in Sec.  178.35(f)(8) to 
improve measurement accuracy and production controls, and to ensure a 
business is not using the allowable differences to disadvantage 
consumers while at the same time maintaining safety compliance?
    5. What would be the impacts of PHMSA reconsidering the allowable 
differences on stamped tare weight as opposed to actual tare weight and 
applying a 0.5 percent tolerance for cylinders 25 pounds or 
less? How would PHMSA define a requirement to follow ``good quality 
control practices'' as suggested in the NCWM petition?

    Issued in Washington, DC, on June 3, 2024.
William S. Schoonover,
Associate Administrator for Hazardous Materials Safety, Pipeline and 
Hazardous Materials Safety Administration.
[FR Doc. 2024-12395 Filed 6-5-24; 8:45 am]
BILLING CODE 4910-60-P