This site displays a prototype of a “Web 2.0” version of the daily
Federal Register. It is not an official legal edition of the Federal
Register, and does not replace the official print version or the official
electronic version on GPO’s govinfo.gov.
The documents posted on this site are XML renditions of published Federal
Register documents. Each document posted on the site includes a link to the
corresponding official PDF file on govinfo.gov. This prototype edition of the
daily Federal Register on FederalRegister.gov will remain an unofficial
informational resource until the Administrative Committee of the Federal
Register (ACFR) issues a regulation granting it official legal status.
For complete information about, and access to, our official publications
and services, go to
About the Federal Register
on NARA's archives.gov.
The OFR/GPO partnership is committed to presenting accurate and reliable
regulatory information on FederalRegister.gov with the objective of
establishing the XML-based Federal Register as an ACFR-sanctioned
publication in the future. While every effort has been made to ensure that
the material on FederalRegister.gov is accurately displayed, consistent with
the official SGML-based PDF version on govinfo.gov, those relying on it for
legal research should verify their results against an official edition of
the Federal Register. Until the ACFR grants it official status, the XML
rendition of the daily Federal Register on FederalRegister.gov does not
provide legal notice to the public or judicial notice to the courts.
Proposed Rule
Enter a search term or FR citation e.g.
88 FR 38230 FR 78782024-13208USDA09/05/24RULE0503-AA39SORN
Choosing an item from
full text search results
will bring you to those results. Pressing enter in the search box
will also bring you to search results.
Choosing an item from
suggestions
will bring you directly to the content.
Comments must be received on or before September 2, 2025.
Table of Contents
Enhanced Content - Table of Contents
This table of contents is a navigational tool, processed from the
headings within the legal text of Federal Register documents.
This repetition of headings to form internal navigation links
has no substantive legal effect.
Hazardous Materials: Adoption of Department of Transportation Special Permit 21379
Public Comments
Enhanced Content - Public Comments
Comments are no longer being accepted.
See DATES for details.
173 comments have
been received at Regulations.gov.
Agencies review all submissions and may choose to redact, or withhold,
certain submissions (or portions thereof). Submitted comments may not be
available to be read until the agency has approved them.
Docket Title
Document ID
Comments
Hazardous Materials: Adopt DOT-SP 21379 into the HMR
FederalRegister.gov retrieves relevant information about this document
from Regulations.gov to provide users with additional context. This
information is not part of the official Federal Register document.
Hazardous Materials: Adopt DOT-SP 21379 into the HMR
Document page views are updated periodically throughout the day and are
cumulative counts for this document. Counts are subject to sampling,
reprocessing and revision (up or down) throughout the day.
Page views
962
as of
10/06/2026 at 12:15 am EDT
Other Formats
Enhanced Content - Other Formats
This document is also available in the following formats:
This PDF is FR Doc. 2025-12100 as it appeared on Public Inspection on
06/27/2025 at 4:15 pm.
It was viewed
11
times while on Public Inspection.
If you are using public inspection listings for legal research, you
should verify the contents of the documents against a final, official
edition of the Federal Register. Only official editions of the
Federal Register provide legal notice of publication to the public and judicial notice
to the courts under 44 U.S.C. 1503 & 1507.
Learn more here.
Published Document: 2025-12100 (90 FR 28552)
This document has been published in the Federal Register. Use the PDF linked in the document sidebar for the official electronic format.
AGENCY:
Pipeline and Hazardous Materials Safety Administration (PHMSA), Department of Transportation (DOT).
ACTION:
Notice of proposed rulemaking (NPRM).
SUMMARY:
This NPRM proposes to adopt the provisions of DOT special permit (SP) 21379 into the hazardous materials regulations to streamline the transportation of large refrigerating machines filled with flammable gases.
DATES:
Comments must be received on or before September 2, 2025.
ADDRESSES:
You may submit comments identified by the Docket Number PHMSA-2025-0102 using any of the following methods:
E-Gov Web: https://www.regulations.gov.
This site allows the public to enter comments on any
Federal Register
notice issued by any agency. Follow the online instructions for submitting comments.
Mail:
Docket Management System: U.S. Department of Transportation, 1200 New Jersey Avenue SE, West Building Ground Floor, Room W12-140, Washington, DC 20590-0001.
Hand Delivery:
U.S. DOT Docket Management System: West Building Ground Floor, Room W12-140, 1200 New Jersey Avenue SE, between 9 a.m. and 5 p.m., Monday through Friday, except Federal holidays.
Fax:
1-202-493-2251.
Instructions:
Please include the docket number PHMSA-2025-0102 at the beginning of your comments. If you submit your comments by mail, submit two copies. If you wish to receive confirmation that PHMSA received your comments, include a self-addressed stamped postcard. Internet users may submit comments at
https://www.regulations.gov.
Privacy Act:
In accordance with 5 U.S.C. 553(c), DOT solicits comments from the public to inform its rulemaking process. DOT posts these comments, without edit, including any personal information the commenter provides, to
https://www.regulations.gov,
as described in the system of records notice (DOT/ALL-14 FDMS), which can be reviewed at
https://www.dot.gov/privacy.
Confidential Business Information:
Confidential Business Information (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. It is important that you clearly designate the comments submitted as CBI if: your comments responsive to this document contain commercial or financial information that is customarily treated as private; you actually treat such information as private; and your comment is relevant or responsive to this notice. You may ask PHMSA to provide confidential treatment to information you give to the agency by taking the following steps: (1) mark each page of the original document submission containing CBI as “Confidential”; (2) send PHMSA, along with the original document, a second copy of the original document with the CBI deleted; and (3) explain why the information that you are submitting is CBI. Submissions containing CBI should be sent to Ryan Larson, Standards and Rulemaking Division, Pipeline and Hazardous Materials Safety Administration (PHMSA), 2nd Floor, 1200 New Jersey Avenue SE, Washington, DC 20590-0001, or by email at
ryan.larson@dot.gov.
Any materials PHMSA receives that is not specifically designated as CBI will be placed in the public docket.
Docket:
For access to the docket to read background documents or comments received, go to
http://www.regulations.gov.
Follow the online instructions for accessing the docket. Alternatively, you may review the documents in person at the street address listed above.
FOR FURTHER INFORMATION CONTACT:
Ryan Larson, Transportation Regulations Specialist, 1200 New Jersey Avenue SE, Washington, DC 20590, 202-366-8553,
ryan.larson@dot.gov.
SUPPLEMENTARY INFORMATION:
I. General Discussion
PHMSA is proposing to revise § 173.306 to provide an exception from the Hazardous Materials Regulations (HMR; Parts 171-180) for certain specification packaging requirements for large refrigerating machines containing certain flammable gases. The American Innovation and Manufacturing Act (AIM),[1]
signed into law in December 2020, required manufacturers to transition from higher Global Warming Potential (GWP) refrigerants, such as American Society of Heating, Refrigerating and Air-Conditioning Engineers (ASHRAE) Group A1 gasses, currently classified as Division 2.2 non-flammable gases, to more environmentally friendly refrigerants with lower GWP. A majority of these
( printed page 28553)
lower GWP refrigerants are flammable, but fall within the lower flammability category or may only propagate flame front at temperatures >23 C. All of the low GWP liquefied gases (refrigerants) described in this notice fall within GHS Category 1B and therefore ASHRAE Class 2L.
Currently, § 173.306(e)(1) and (2) provide an exception for refrigerating machines containing Group A1 refrigerant, as classified in ANSI/ASHRAE Standard 15, or not more than 50 pounds of refrigerant other than Group A1, from the specification packaging requirements of the HMR. Adopting DOT-SP 21379 into the HMR would expand the existing 5,000 lb. limit for Group A1 refrigerant, as classified in ANSI/ASHRAE Standard 15, to 5,000 lb. for low flammability gases meeting the criteria of the United Nations Globally Harmonized System (GHS) of Classification and Labelling of Chemicals (Seventh Revised Edition) Category 1B, or the equivalent found in American Society of Heating, Refrigerating and Air-Conditioning Engineers (ASHRAE) A2L Standard 34. Additional transport conditions such as vehicle type and markings are proposed for transporting refrigerating machines containing flammable gases. PHMSA does not expect the proposed revisions to have any adverse impact on safety.
II. Regulatory Analysis and Notices
A. Legal Authority
This proposed rule is published under the authority of the Secretary of Transportation set forth in the Federal Hazardous Materials Transportation laws (49 U.S.C. 5101et seq.) and delegated to the PHMSA Administrator pursuant to 49 CFR 1.97.
B. Executive Orders 12866; Regulatory Planning and Review
Executive Order (E.O.) 12866 (“Regulatory Planning and Review”),[2]
as implemented by DOT Order 2100.6B (“Policies and Procedures for Rulemaking”), requires agencies to regulate in the “most cost-effective manner,” to make a “reasoned determination that the benefits of the intended regulation justify its costs,” and to develop regulations that “impose the least burden on society.” DOT Order 2100.6B specifies that regulations should generally “not be issued unless their benefits are expected to exceed their costs.” In arriving at those conclusions, E.O. 12866 requires that agencies should consider “both quantifiable measures . . . and qualitative measures of costs and benefits that are difficult to quantify” and “maximize net benefits . . . unless a statute requires another regulatory approach.” E.O. 12866 also requires that “agencies should assess all costs and benefits of available regulatory alternatives, including the alternative of not regulating.” DOT Order 2100.6B directs that PHMSA and other Operating Administrations must generally choose the “least costly regulatory alternative that achieves the relevant objectives” unless required by law or compelling safety need.
E.O. 12866 and DOT Order 2100.6B also require that PHMSA submit “significant regulatory actions” to the Office of Information and Regulatory Affairs (OIRA) within the Executive Office of the President's Office of Management and Budget (OMB) for review. This proposed rule is a not significant regulatory action pursuant to E.O. 12866; it also has not designated this rule as a “major rule” as defined by the Congressional Review Act (5 U.S.C. 801et seq.).
PHMSA has complied with the requirements in E.O. 12866 as implemented by DOT Order 2100.6B and made a preliminarily determination that this proposed rule would result in cost savings by reducing regulatory burdens and regulatory uncertainty for shippers of refrigerating machines by allowing for their transportation without the need for a special permit. PHMSA expects those cost savings would also result in reduced costs for the public to whom those entities generally transfer a portion of their compliance costs.
C. Executive Orders 14192 and 14219
This proposed rule, if finalized as proposed, is expected to be an E.O. 14192 deregulatory action.[3]
PHMSA seeks data that would be helpful to generate an estimate of the cost savings from this rule. PHMSA's initial estimates are that the total costs of the rule on the regulated community would be less than zero. Nor does this proposed rule does implicate any of the factors identified in section 2(a) of E.O. 14219 indicative of a regulation that is “unlawful . . . [or] that undermine[s] the national interest.” [4]
D. Energy-Related Executive Orders 13211, 14154, and 14156
The President has declared in E.O. 14156 (“Declaring a National Energy Emergency”) [5]
a national emergency to address the United States's inadequate energy development production, transportation, refining, and generation capacity. Similarly, E.O. 14154 (“Unleashing American Energy”) [6]
asserts a Federal policy to unleash American energy by ensuing access to abundant supplies of reliable, affordable energy from (inter alia) the removal of “undue burden[s]” on the identification, development, or use of domestic energy resources such as PHMSA-jurisdictional hazardous materials shippers and carrier. PHMSA preliminarily finds this proposed rule is consistent with each of E.O. 14156 and E.O. 14154 because it would not hinder or unduly burden the transportation or production of energy or energy-related products.
However, this proposed rule is not a “significant energy action” under E.O. 13211 (“Actions Concerning Regulations That Significantly Affect Energy Supply, Distribution, or Use”),[7]
which requires Federal agencies to prepare a Statement of Energy Effects for any “significant energy action.” Because this proposed rule is not a significant action under E.O. 12866, it would not have a significant adverse effect on supply, distribution, or energy use; and OIRA has therefore not designated this proposed rule as a significant energy action.
PHMSA analyzed this proposed rule in accordance with the principles and criteria contained in E.O. 13132 (“Federalism”) [8]
and the Presidential Memorandum (“Preemption”) published in the
Federal Register
on May 22, 2009.[9] E.O. 13132 requires agencies to assure meaningful and timely input by State and local officials in the development of regulatory policies that may have “substantial direct effects on the States, on the relationship between the National Government and the States, or on the distribution of power and responsibilities among the various levels of government.” The Federal Hazardous Materials Transportation laws contain an express preemption provision at 49 U.S.C. 5125(b) that preempts state, local, and tribal requirements on certain covered subjects, unless the non-federal requirements are “substantively the same” as the federal requirements, including the following:
(1) The designation, description, and classification of hazardous material;
( printed page 28554)
(2) The packing, repacking, handling, labeling, marking, and placarding of hazardous material;
(3) The preparation, execution, and use of shipping documents related to 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, manufacture, fabrication, inspection, marking, maintenance, recondition, repair, or testing of a packaging or container represented, marked, certified, or sold as qualified for use in transporting hazardous material in commerce.
This proposed rule addresses covered subject items listed in paragraph 1 above and would preempt state, local, and Tribal requirements not meeting the “substantively the same” standard. While the proposed rule may operate to preempt some State requirements, it would not impose any regulation that has substantial direct effects on the States, the relationship between the National Government and the States, or the distribution of power and responsibilities among the various levels of government. The preemptive effect of the regulatory amendments in this proposed rule is limited to the minimum level necessary to achieve the objectives of the Federal Hazardous Materials Transportation Laws. Therefore, the consultation and funding requirements of E.O. 13132 do not apply.
F. Regulatory Flexibility Act
The Regulatory Flexibility Act (5 U.S.C. 601et seq.) requires Federal agencies to conduct an Initial Regulatory Flexibility Analysis (IRFA) for a proposed rule subject to notice-and-comment rulemaking under the APA unless the agency head certifies that the proposed rule in the rulemaking would not have a significant economic impact on a substantial number of small entities. E.O. 13272 (“Proper Consideration of Small Entities in Agency Rulemaking”) [10]
obliges agencies to establish procedures promoting compliance with the Regulatory Flexibility Act. DOT posts its implementing guidance on a dedicated web page.[11]
This proposed rule was developed in accordance with E.O. 13272 and DOT implementing guidance to ensure compliance with the Regulatory Flexibility Act. The proposed rule is expected to reduce burdens. Therefore, PHMSA certifies the proposed rule does not have a significant impact on a substantial number of small entities.
G. Unfunded Mandates Reform Act of 1995
The Unfunded Mandates Reform Act (UMRA, 2 U.S.C. 1501et seq.) requires agencies to assess the effects of Federal regulatory actions on State, local, and Tribal governments, and the private sector. For any proposed or direct final rule that includes a Federal mandate that may result in the expenditure by state, local, and Tribal governments, in the aggregate of $100 million or more (in 1996 dollars) in any given year, the agency must prepare, amongst other things, a written statement that qualitatively and quantitatively assesses the costs and benefits of the Federal mandate.
This proposed rule does not impose unfunded mandates under UMRA because it does not result in costs of $100 million or more (in 1996 dollars) per year for either State, local, or Tribal governments, or to the private sector.
H. National Environmental Policy Act
The National Environmental Policy Act (NEPA, 42 U.S.C. 4321et seq.) requires that Federal agencies assess and consider the impact of major Federal actions on the human and natural environment.
PHMSA analyzed this proposed rule in accordance with NEPA and has preliminarily determined that the rulemaking would not adversely affect safety and therefore would not significantly affect the quality of the human and natural environment. The public is invited to comment on the impact of the proposed action.
PHMSA analyzed this proposed rule according to the principles and criteria in E.O. 13175 (“Consultation and Coordination with Indian Tribal Governments”) [12]
and DOT Order 5301.1A (“Department of Transportation Tribal Consultation Policies and Procedures”). E.O. 13175 requires agencies to assure meaningful and timely input from Tribal government representatives in the development of rules that significantly or uniquely affect Tribal communities by imposing “substantial direct compliance costs” or “substantial direct effects” on such communities or the relationship or distribution of power between the Federal government and Tribes.
PHMSA assessed the impact of the proposed rule and determined that it would not significantly or uniquely affect Tribal communities or Indian Tribal governments. The rulemaking's regulatory amendments have a broad, national scope; therefore, this proposed rule would not significantly or uniquely affect Tribal communities, much less impose substantial compliance costs on Native American Tribal governments or mandate Tribal action. For these reasons, PHMSA has concluded that the funding and consultation requirements of E.O. 13175 and DOT Order 5301.1A do not apply.
J. Paperwork Reduction Act
The Paperwork Reduction Act (44 U.S.C. 3501et seq.) and its implementing regulations at 5 CFR 1320.8(d) requires that PHMSA provide interested members of the public and affected agencies with an opportunity to comment on information collection and recordkeeping requests. This rulemaking would not create, amend, or rescind any existing information collections. However, this rulemaking eliminates the need for persons to renew a special permit, resulting in a decrease in paperwork burden for special permit holders. PHMSA estimates the reduction in information collection burden as follows:
OMB Control No. 2137-0051:
Rulemaking, Special Permits, and Preemption Requirements.
Decrease in Annual Number of Respondents:
10.
Decrease in Annual Responses:
10.
Decrease in Annual Burden Hours:
14.
Decrease in Annual Burden Cost:
$0.
PHMSA specifically requests comments on the information collection and recordkeeping burdens associated with developing, implementing, and maintaining these requirements for approval under this NPRM. Address written comments to the Dockets Unit as identified in the
ADDRESSES
section of this NPRM. PHMSA must receive comments regarding information collection burdens prior to the close of the comment period identified in the
DATES
section of this NPRM. Notwithstanding any other provision of law, no person is required to respond to a collection of information unless such collection displays a valid Office of Management and Budget (OMB) control number.
Please direct your requests for a copy of this information collection to Steven Andrews, Office of Hazardous Materials Standards (PHH-12), Pipeline and
( printed page 28555)
Hazardous Materials Safety Administration, 1200 New Jersey Avenue SE, 2nd Floor, Washington, DC 20590-0001.
E.O. 13609 (“Promoting International Regulatory Cooperation”) [13]
requires agencies consider whether the impacts associated with significant variations between domestic and international regulatory approaches are unnecessary or may impair the ability of American business to export and compete internationally. In meeting shared challenges involving health, safety, labor, security, environmental, and other issues, international regulatory cooperation can identify approaches that are at least as protective as those that are or would be adopted in the absence of such cooperation. International regulatory cooperation can also reduce, eliminate, or prevent unnecessary differences in regulatory requirements.
Similarly, the Trade Agreements Act of 1979 (Pub. L. 96-39), as amended by the Uruguay Round Agreements Act (Pub. L. 103-465), prohibits Federal agencies from establishing any standards or engaging in related activities that create unnecessary obstacles to the foreign commerce of the United States. For purposes of these requirements, Federal agencies may participate in the establishment of international standards, so long as the standards have a legitimate domestic objective, such as providing for safety, and do not operate to exclude imports that meet this objective. The statute also requires consideration of international standards and, where appropriate, that they be the basis for U.S. standards.
PHMSA engages with international standards setting bodies to protect the safety of the American public. PHMSA has assessed the effects of the proposed rule and has determined that its regulatory amendments would not cause unnecessary obstacles to foreign trade.
E.O. 14028 (“Improving the Nation's Cybersecurity”) [14]
directed the Federal government to improve its efforts to identify, deter, and respond to “persistent and increasingly sophisticated malicious cyber campaigns.” PHMSA has considered the effects of the proposed rule and has determined that its regulatory amendments would not materially affect the cybersecurity risk profile for affected entities.
(1)(i) Each pressure vessel may not contain more than 5,000 pounds of Group A1 refrigerant as classified in ANSI/ASHRAE Standard 15, more than 5,000 pounds of GHS Category 1B or equivalent ASHRAE A2L refrigerant, or not more than 50 pounds of refrigerant other than those specified above.
(ii) Machines or components having two or more charged vessels may not contain an aggregate of more than 2,000 pounds of Group I refrigerant; an aggregate of more than 2,000 pounds of GHS Category 1B or equivalent ASHRAE A2L Standard 34-2019 refrigerant (IBR, see § 171.7 of this subchapter); or more than 100 pounds of refrigerant other than those specified above.
* * * * *
(ix) Each new (unused) refrigerating machine or component thereof containing a Division 2.1 gas must be transported:
(A) On a motor vehicle utilizing an open flat-bed trailer;
(B) On an open flat-bed rail car; or
(C) In a well-ventilated closed transport vehicle (such as a trailer or rail car).
* * * * *
(2)
Used refrigerating machines
—(i)
Packaging.
Reconditioned (used) refrigerating machines (UN2857, Div. 2.2 or UN3358, Div. 2.1) may be excepted from the marking requirements of § 172.302(c) of this subchapter and transported by motor vehicle when they conform to the requirements prescribed in paragraph (e)(1) of this section, are secured or permanently attached to the motor vehicle, and are:
* * * * *
(3) Each refrigerating machine or component thereof containing a Division 2.1 gas must be marked on each side and each end with the identification number marking in accordance with the requirements of § 172.302 of this subchapter.
(4) For a refrigerating machine or component thereof containing a Division 2.1 gas contained in or on a transport vehicle or rail car, if the identification number marking on the refrigerating machine or component thereof in accordance with § 172.302(a) of this subchapter is not visible, the transport vehicle or rail car must be marked as required by § 172.332 of this subchapter on each side and each end with the identification number.
* * * * *
Issued in Washington, DC, on June 26, 2025, under the authority delegated in 49 CFR 1.97.
11.
DOT, “Rulemaking Requirements Related to Small Entities,”
https://www.transportation.gov/regulations/
rulemaking-requirements-concerning-small-entities (last accessed Sept 3, 2024).
173 comments have been received at Regulations.gov.
Agencies review all submissions and may choose to redact, or withhold, certain submissions (or portions thereof). Submitted comments may not be available to be read until the agency has approved them.