# Hazardous Materials: Harmonization With International Standards

- **operation:** document
- **citation:** 91 FR 5996
- **title:** Hazardous Materials: Harmonization With International Standards
- **source type:** rulemaking
- **agency:** Pipeline and Hazardous Materials Safety Administration
- **status:** proposed
- **official:** true
- **published on:** 2026-02-10
- **effective on:** Not available
- **summary:** PHMSA proposes to amend the Hazardous Materials Regulations to adopt certain international regulations and standards related to proper shipping names, hazard classes, packing groups, special provisions, packaging authorizations, air transport quantity limitations, and vessel stowage requirements. These amendments are intended to maintain consistency with the latest international standards and regulations, and to reduce costs to entities or individuals within the United States or to otherwise lower the cost of regulations on the United States economy.
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- **source url:** https://www.federalregister.gov/documents/2026/02/10/2026-02575/hazardous-materials-harmonization-with-international-standards
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Federal Register, Volume 91 Issue 27 (Tuesday, February 10, 2026) [Federal Register Volume 91, Number 27 (Tuesday, February 10, 2026)] [Proposed Rules] [Pages 5996-6071] From the Federal Register Online via the Government Publishing Office [ www.gpo.gov ] [FR Doc No: 2026-02575] [[Page 5995]] Vol. 91 Tuesday, No. 27 February 10, 2026 Part II Department of Transportation ----------------------------------------------------------------------- Pipeline and Hazardous Materials Safety Administration ----------------------------------------------------------------------- 49 CFR Parts 171, 172, 173, et al. Hazardous Materials: Harmonization With International Standards; Proposed Rule Federal Register / Vol. 91 , No. 27 / Tuesday, February 10, 2026 / Proposed Rules [[Page 5996]] ----------------------------------------------------------------------- DEPARTMENT OF TRANSPORTATION Pipeline and Hazardous Materials Safety Administration 49 CFR Parts 171, 172, 173, 175, 176, 178, and 180 [Docket No. PHMSA-2023-0111 (HM-215R)] RIN 2137-AF64 Hazardous Materials: Harmonization With International Standards AGENCY: Pipeline and Hazardous Materials Safety Administration (PHMSA), Department of Transportation (DOT). ACTION: Notice of proposed rulemaking (NPRM). ----------------------------------------------------------------------- SUMMARY: PHMSA proposes to amend the Hazardous Materials Regulations to adopt certain international regulations and standards related to proper shipping names, hazard classes, packing groups, special provisions, packaging authorizations, air transport quantity limitations, and vessel stowage requirements. These amendments are intended to maintain consistency with the latest international standards and regulations, and to reduce costs to entities or individuals within the United States or to otherwise lower the cost of regulations on the United States economy. DATES: Comments must be received by April 13, 2026. To the extent possible, PHMSA will consider late-filed comments while a final rule is developed. ADDRESSES: You may submit comments by any of the following methods: Federal Rulemaking Portal: http://www.regulations.gov . Follow the online instructions for submitting comments. Fax: 1-202-493-2251. Mail: Docket Management System; U.S. Department of Transportation, Docket Operations, M-30, Ground Floor, Room W12-140, 1200 New Jersey Avenue SE, Washington, DC 20590-0001. Hand Delivery: U.S. Department of Transportation, Docket Operations, M-30, Ground Floor, Room W12-140, 1200 New Jersey Avenue SE, Washington, DC 20590-0001 between 9 a.m. and 5 p.m., Monday through Friday, except Federal holidays. Instructions: Include the agency name and docket number PHMSA-2023- 0111 (HM-215R) or RIN 2137-AF64 for this rulemaking at the beginning of your comment. All comments received will be posted without change to http://www.regulations.gov , including any personal information provided. If sent by mail, comments must be submitted in duplicate. Persons wishing to receive confirmation of receipt of their comments must include a self-addressed stamped postcard. Docket: For access to the dockets to read background documents including the Preliminary Regulatory Impact Analysis (PRIA) or comments received, go to http://www.regulations.gov or DOT's Docket Operations Office (see ADDRESSES). 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 (5 U.S.C. 552), CBI is exempt from public disclosure. If your comments in response to this NPRM 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 NPRM, it is important that you clearly designate the submitted comments as CBI. Pursuant to 49 CFR 105.30, you may ask PHMSA to provide confidential treatment to the 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 a copy of the original document with the CBI deleted along with the original, unaltered document; and (3) explain why the information you are submitting is CBI. Submissions containing CBI should be sent to Steven Andrews, 1200 New Jersey Avenue SE, DOT: PHMSA-PHH-10, Washington, DC 20590-0001. Any comment PHMSA receives that is not explicitly designated as CBI will be placed in the public docket. FOR FURTHER INFORMATION CONTACT: Candace Casey, Standards and Rulemaking, at 202-366-8553, Pipeline and Hazardous Materials Safety Administration, U.S. Department of Transportation, 1200 New Jersey Avenue SE, East Building, 2nd Floor, Washington, DC 20590-0001. SUPPLEMENTARY INFORMATION: Table of Contents I. Executive Summary II. Background III. Incorporation by Reference Discussion Under 1 CFR Part 51 IV. Amendments Not Being Proposed for Adoption V. Section-by-Section Review of NPRM Proposals VI. Regulatory Analyses and Notices A. Legal Authority B. Executive Order 12866; Regulatory Planning and Review C. Executive Orders 14192 and 14219 D. Energy-Related Executive Orders 13211, 14154, and 14156 E. Executive Order 13132: Federalism F. Regulatory Flexibility Act G. Unfunded Mandates Reform Act of 1995 H. National Environmental Policy Act I. Executive Order 13175: Consultation and Coordination With Indian Tribal Governments J. Privacy Act K. Paperwork Reduction Act L. Executive Order 13609 and International Trade Analysis M. National Technology Transfer and Advancement Act N. Cybersecurity and Executive Order 14028 O. Severability I. Executive Summary The Secretary of Transportation is directed by 49 U.S.C. 5120 to ensure that domestic regulations for the transportation of hazardous materials are generally consistent with the latest international standards and requirements, unless such standards or requirements are unnecessary or unsafe, or a more stringent safety standard is in the public interest. Consistent with this statutory requirement, the Pipeline and Hazardous Materials Safety Administration proposes to amend the Hazardous Materials Regulations (HMR) to adopt certain international regulations and standards, including changes to material incorporated by reference, hazardous materials descriptions and proper shipping names (PSN), hazard classes, packing groups (PG), special provisions, packaging authorizations, air transport quantity limitations, and vessel stowage requirements. PHMSA anticipates that the adoption of the amendments proposed in this NPRM will maintain the current levels of safety achieved under the HMR. Harmonizing the HMR with international consensus standards is expected to also reduce delays and interruptions in the transportation of hazardous materials and promote the efficient and free flow of commerce by eliminating unnecessary, outdated, and conflicting regulatory requirements. Overall, the proposed amendments are intended to reduce costs to entities or individuals within the United States or otherwise lower the cost of regulations on the United States economy. The following list summarizes noteworthy proposals set forth in this NPRM: Incorporation by Reference: PHMSA proposes to incorporate by reference updated versions of the following international hazardous materials regulations and standards: the 2025-2026 edition of the International [[Page 5997]] Civil Aviation Organization Technical Instructions for the Safe Transport of Dangerous Goods by Air (ICAO Technical Instructions); Amendment 42-24 to the International Maritime Dangerous Goods Code (IMDG Code); the 2023 edition of Transport Canada's Transportation of Dangerous Goods (TDG) Regulations; and the 23rd revised edition of the United Nations Recommendations on the Transport of Dangerous Goods-- Model Regulations (UN Model Regulations). Amendments to the Hazardous Materials Table: PHMSA proposes amendments to the Hazardous Materials Table (HMT; Sec. 172.101) to add, to revise, or to remove certain PSNs, hazard classes, PGs, SPs, packaging authorizations, bulk packaging requirements, and passenger and cargo aircraft maximum quantity limits. Increase in authorized amounts of certain gases transported as limited quantities: For modes other than air transportation, PHMSA proposes to extend the relief provided by the limited quantity provisions to four Division 2.2 (non-flammable and non-poisonous) compressed gases. This amendment would authorize these materials for transport as a limited quantity material in quantities up to 1000 ml (34 fluid ounces) per package, when transported in DOT specification cylinders or UN pressure receptacles. These materials are: ``UN1006, Argon,'' ``UN1013, Carbon dioxide,'' ``UN1046, Helium,'' and ``UN1066, Nitrogen.'' Amendments to the Organic Peroxides Table: PHMSA proposes amendments to the organic peroxides table in Sec. 173.225, which lists individual organic peroxide formulations that are authorized for transportation without prior approval. The proposed amendments include the addition of three new formulations: (Dibenzoyl peroxide, 2,5- dimethyl-2,5-di-(tert-butylperoxy) hexane, and methyl ethyl ketone peroxide (with a concentration limit of available oxygen Amendments to provisions for the transport of tetramethylammonium hydroxide: PHMSA proposes to adopt several changes pertaining to entries for Tetramethylammonium hydroxide (TMAH) to maintain consistency with changes adopted in several international standards in response to new incident and test data showing a toxicity hazard in addition to the previously identified corrosivity hazard. The proposed amendments include the addition of a new HMT entry for aqueous solutions, and revisions to the hazard classification, proper shipping name, or both, for existing entries of PG II and PG III TMAH solutions (UN1835), reclassification of TMAH solids (UN3423), the addition of two new special provisions, and revised packaging authorizations. New provisions for sodium ion batteries: PHMSA proposes to add new HMT entries and transport provisions for sodium ion batteries to maintain consistency with changes adopted in the 2025-2026 edition of the ICAO Technical Instructions and the 23rd revised edition of the UN Model Regulations. The new provisions in the international regulations regulate sodium ion batteries in the same way as lithium ion batteries and are intended to address anticipated increases in the use of sodium ion batteries as an alternative to lithium ion batteries. New state-of-charge provisions for certain lithium and sodium ion batteries transported by air: PHMSA proposes expanding current state-of-charge requirements to certain lithium and sodium ion batteries transported by air. The new provision would limit the amount of stored energy to 30 percent or less of the battery's capacity at the time of transport. Improved Emergency Response Information for Lithium Batteries Transported as ``UN3536, Lithium batteries installed in cargo transport unit lithium ion batteries or lithium metal batteries: '' PHMSA proposes to amend Special Provision 389 to require that the emergency response information for UN3536 specifically identify the predominant type of energy storage battery installed in the unit (e.g., lithium ion batteries or lithium metal batteries) and provide information on immediate methods for handling fires. When determining the predominant type of energy storage battery, PHMSA encourages shippers to consider which battery type provides electrical power to external devices or the power grid when units transported under UN3536 are in operation. Exceptions for ammonium nitrate hot concentrated solution: PHMSA proposes to add specific conditions under which solutions of ammonium nitrate (hot concentrated solution) can be transported under the HMT entry ``UN2426, Ammonium nitrate'' or can qualify for exception from regulation under the HMR. The proposed requirements for solutions of ammonium nitrate to be transported under UN2426 are based on concentration, water content, combustible material content, chlorine content, pH level, and temperature. These requirements were adopted in the 23rd revised edition of the UN Model Regulations to harmonize transport conditions and requirements multimodally. Exceptions for nitrocellulose membrane filters used in rapid test devices: PHMSA proposes to add a new special provision with specific packaging requirements for ``UN3270, Nitrocellulose membrane filters, with not more than 12.6% nitrogen, by dry mass'' to be excepted from regulation. These materials are most notably used in rapid test devices for infectious diseases and as substrates for bioanalytical tests as well as pregnancy tests. PHMSA's proposal would maintain consistency with changes adopted in the 23rd revised edition of the UN Model Regulations to facilitate further the transport of these items. PHMSA anticipates that the proposals in the NPRM will produce safety benefits from harmonizing domestic and international regulations. PHMSA solicits comment on the need, benefits, and costs of the proposed HMR revisions; impact on safety and the environment; and any other relevant information. PHMSA also solicits comment regarding approaches to reducing the costs of the proposed HMR revisions while maintaining or increasing safety benefits and on any other specific changes (e.g., greater flexibility regarding a particular proposal) that might improve the rulemaking. As further explained in the PRIA, PHMSA expects that the aggregate benefits of the amendments proposed in this NPRM for United States entities or individuals justify their aggregate costs. II. Background The Federal Hazardous Materials Transportation Law (49 U.S.C. 5101, et seq.) directs PHMSA to participate in international standard-setting forums for the transportation of hazardous materials in commerce and encourages alignment of the HMR with those standards (49 U.S.C. 5120). Harmonization of the HMR with international standards and regulations can reduce the costs and other burdens of complying with multiple or inconsistent safety requirements between nations. PHMSA actively participates in the development of international standards for the transportation of hazardous materials and promotes the adoption of standards consistent with the HMR. Maintaining consistency between [[Page 5998]] current international standards and the HMR enhances safety by, among other things: (1) ensuring the HMR are informed by the latest international best practices and lessons learned; (2) improving understanding of, and compliance with, pertinent international requirements; (3) facilitating the flow of hazardous materials in commerce and avoiding risks to the public and the environment from handling and potential releases of hazardous materials due to delays or interruptions in transportation; and (4) enabling consistent emergency response procedures in the event of a hazardous materials incident. When considering alignment of the HMR with new or amended international standards, PHMSA reviews each standard on its own merit, assesses its overall impact on transportation safety, and analyzes the economic implications associated with its adoption. PHMSA's goal is to harmonize with international standards without diminishing the level of safety currently provided by the HMR or imposing undue burdens on the regulated community. In 1990, PHMSA's predecessor, the Research and Special Programs Administration (RSPA), comprehensively revised the HMR for greater consistency with the UN Model Regulations.\1\ The UN Model Regulations constitute a set of recommendations issued by the United Nations Sub- Committee of Experts (UNSCOE) on the Transport of Dangerous Goods and on the Globally Harmonized System of Classification and Labelling of Chemicals (GHS). The UN Model Regulations are amended and updated biennially by the UNSCOE and serve as the basis for national, regional, and international modal regulations, including the ICAO Technical Instructions and IMDG Code. PHMSA routinely updates the HMR to incorporate these biennial amendments. --------------------------------------------------------------------------- \1\ 55 FR 52401 (\De\c. 21, 1990). --------------------------------------------------------------------------- PHMSA has evaluated the latest biennial updates to the international regulations and consensus standards and proposes to revise the HMR to adopt changes consistent with revisions to the 2025- 2026 edition of the ICAO Technical Instructions, the Amendment 42-24 to the IMDG Code, and the 23rd revised edition of the UN Model Regulations, all of which were published by or in effect on January 1, 2025.\2\ PHMSA also proposes to incorporate by reference these revised international regulations, as well as several new or updated International Organization for Standards (ISO) standards. The regulations incorporated by reference are authorized for use for domestic and international transportation, under specific conditions, in part 171, subpart C of the HMR. --------------------------------------------------------------------------- \2\ Amendment 42-24 of the IMDG Code became mandatory on January 1, 2025. Voluntary compliance began on January 1, 2024. --------------------------------------------------------------------------- On December 9, 2024, PHMSA issued a notice of enforcement discretion, stating that PHMSA and other Federal agencies that enforce the HMR (i.e., the Federal Railroad Administration (FRA), the Federal Aviation Administration (FAA), the Federal Motor Carrier Safety Administration (FMCSA), and the United States Coast Guard (USCG)) will not take enforcement action against any offeror or carrier who follows the 2025-2026 Edition of the ICAO Technical Instructions and Amendment 42-24 of the IMDG Code when all or part of the transportation is by air with respect to the ICAO Technical Instructions, or all or part of the transportation is by vessel with respect to the IMDG Code, during the pendency of this rulemaking proceeding.\3\ For transport by rail and highway to, from, or within the United States, PHMSA also stated that these agencies will not take enforcement action against any offeror or carrier who offers or accepts hazardous materials identified and described on a shipping paper, or packages either marked or labeled in accordance with these standards--provided that appropriate emergency response information consistent with 49 CFR part 172, subpart G accompanies the shipment. The December 9, 2024, notice of enforcement discretion remains in effect until withdrawn or otherwise modified.\4\ --------------------------------------------------------------------------- \3\ PHMSA, Notice of Enforcement Policy Regarding International Standards (Dec. 9, 2024), available at: https://www.phmsa.dot.gov/regulatory-compliance/phmsa-guidance/notice-enforcement-policy-regarding-international-standards . \4\ PHMSA notes that items described and packaged for transportation under the respective international standards as UN0514 and UN3559, ``Fire Suppressant Dispersing Devices,'' must first be approved by the Associate Administrator in accordance with 49 CFR 173.56. --------------------------------------------------------------------------- III. Incorporation by Reference Discussion Under 1 CFR Part 51 The National Technology Transfer and Advancement Act of 1995 (NTTAA; Pub. L. 104-113) directs Federal agencies to use standards developed by voluntary consensus standards bodies in lieu of government-written standards whenever possible. Voluntary consensus standards bodies develop, establish, or coordinate technical standards using agreed-upon procedures. PHMSA currently incorporates by reference into the HMR all or parts of numerous standards and specifications published by these bodies, which are otherwise known as standard development organizations (SDOs). In general, SDOs update and revise their published standards every two to five years to reflect modern technology and best technical practices. The Office of Management and Budget (OMB) issued Circular A-119, Federal Participation in the Development and Use of Voluntary Consensus Standards and in Conformity Assessment Activities, to implement Section 12(d) of the NTTAA. This circular provides guidance for Federal agencies participating in voluntary consensus standards bodies and describes procedures for satisfying the reporting requirements in the NTTAA. PHMSA is responsible for determining which standards currently referenced in the HMR should be updated, revised, or removed, and which standards should be added to the HMR, under the NTTAA and Circular A- 119. Revisions to materials incorporated by reference in the HMR are handled via the notice-and-comment rulemaking process. PHMSA must also obtain approval from the Office of the Federal Register to incorporate by reference any new materials during that process. The Office of the Federal Register issued a rulemaking that revised 1 CFR 51.5 to require that an agency detail in the preamble of an NPRM the ways the materials it proposes to incorporate by reference are reasonably available to interested parties, or how the agency worked to make those materials reasonably available to interested parties.\5\ Proposed changes to the material incorporated by reference in the HMR are discussed in detail in the Section 171.7 discussion in ``Section V. Section-by-Section Review of NPRM Proposals.'' --------------------------------------------------------------------------- \5\ 79 FR 66278 (Nov. 7, 2014). --------------------------------------------------------------------------- The standards incorporated by reference in this NPRM are reasonably available to interested parties in several ways. The UN Model Regulations and the United Nations Manual of Tests and Criteria (UN Manual of Tests and Criteria) are free and easily accessible to the public on the internet (links are provided in footnotes as part of the section 171.7 discussion in ``Section V. Section-by-Section Review of NPRM Proposals'').\6\ The ICAO Technical [[Page 5999]] Instructions, the IMDG Code, and all ISO standard references are available for interested parties to purchase, either in print or electronic versions through the organizations' websites. In addition, all standards that PHMSA proposes to incorporate by reference in the NPRM will be available for review, free of charge, at the PHMSA Headquarters, 1200 New Jersey Avenue, SE, Washington, DC 20590 during the comment period. Interested persons may email [email protected] to arrange for this in-person review. --------------------------------------------------------------------------- \6\ United Nations, UN Model Regulations 23rd revised edition, (October 8, 2023), available at: https://unece.org/transport/dangerous-goods/un-model-regulations-rev-24 ; United Nations, Manual of Tests and Criteria, Eighth revised edition (November 27, 2023), available at: https://unece.org/transport/standards/transport/dangerous-goods/un-manual-tests-and-criteria-rev8-2023 . --------------------------------------------------------------------------- IV. Amendments Not Being Proposed for Adoption PHMSA has determined that certain elements of updated international regulations and standards should not be adopted into the HMR (49 U.S.C. 5120). PHMSA has also determined that certain transport requirements should be authorized on a case-by-case basis through special permits rather than adopting them for general applicability in the HMR. Additional information about these topics is provided below: Additional regulation for carbon and charcoal--The International Maritime Organization (IMO), through its Sub-Committee on Carriage of Cargoes and Containers (CCC), adopted more stringent requirements than currently exist in the HMR for the transport of carbon (e.g., activated carbon or carbon derived from animal or vegetable origin) in Amendment 42-24 to the IMDG Code. Most notably, the IMO removed the ability to exclude such carbon materials from classification as a Division 4.2 (spontaneously combustible material), i.e., a self-heating material, by way of testing, and consequently the ability to be transported as unregulated. Section 173.124 of the HMR currently requires carbon materials such as charcoal that are potentially spontaneously combustible because of self-heating properties to be tested by performing UN Test N.4, ``Test method for self-heating substances,'' in accordance with the UN Manual of Tests and Criteria (see Section 33.4.3.3) and either classified as a Division 4.2 material or excluded from regulation. This classification or exclusion applies to both bulk and non-bulk (e.g., charcoal packaged for retail sale) quantities of carbon. Materials meeting classification criteria are described as ``UN1361, Carbon, animal or vegetable origin'' or ``UN1362, Carbon, activated'', Division 4.2, and are subject to packaging requirements for bulk and non-bulk quantities, respectively. See Sec. Sec. 173.212 and 173.242 for PG II and Sec. Sec. 173.214 and 173.241 for PG III. In addition, hazardous materials transported under UN1361 and UN1362 are assigned stowage category ``A'', meaning that these materials may be stowed ``on deck'' or ``under deck'' on a cargo or passenger vessel, and that they must be kept as cool as reasonably practicable and protected from sources of heat. These stowage requirements in the HMR are in alignment with the current requirements under Amendment 42-24 of the IMDG Code. In the absence of safety incidents related to the shipment of these materials, as well as the unlikelihood of unpackaged bulk shipments of carbon materials such as charcoal, PHMSA finds that the current requirements in the HMR provide the appropriate level of safety without imposing unnecessary burdens on transportation. More specifically, Amendment 42-24 removed Special Provision 925 from the IMDG Code, which previously provided a blanket exception for non-activated carbon blacks of mineral origin, consignments of carbon that passed tests for self-heating substances UN Test N.4, and carbons produced by a steam activation process. Amendment 42-24 also removed packing provision PP12, which previously authorized the use of bags as packaging for materials transported in closed cargo transport units, for ``UN1361, Carbon.'' In addition, Amendment 42-24 removed Special Provision 223--which was previously applicable to carbon materials assigned to PG III--and permitted substances (except for marine pollutants) covered by the description ``UN1361, Carbon, PG III'' or ``UN1362, Activated carbon, PG III'' to be excepted from the IMDG Code when testing showed that the substances did not meet the established defining criteria for any hazard class or division. Amendment 42-24 replaced Special Provisions 925 and 223 with a new Special Provision 978, which specifically prohibits the use of the UN N.4 test to except carbon from the IMDG Code by limiting its application only to carbon produced by pyrolysis of an organic material such as bone, bamboo, coconut shell, jute, or wood. Special Provision 978 also requires additional precautions, such as a 14-day weathering period and periodic monitoring, while the material is stowed during transport. These changes also impacted the stowage requirements for materials transported in bulk containers with the aim of facilitating the dissipation and removal of accumulated heat generated by large amounts of densely stowed charcoal. The IMO adopted the changes in Amendment 42-24 of the IMDG Code following incidents caused by spontaneous combustion of unpackaged bulk shipments of charcoal on board several vessels. The IMO concluded that removing Special Provisions 223 and 925 was needed because these special provisions could not be applied properly across all shipments given that charcoal is often manufactured at different remote production sites (charcoal piles) and consignments are often comprised of charcoal from different origins with different properties rather than being manufactured under standardized conditions. PHMSA is not proposing to incorporate the changes adopted in Amendment 42-24 of the IMDG Code. While largely aimed at addressing fires associated with the movement of unpackaged bulk shipments of charcoal, the current IMDG Code requirements also apply to smaller packages of charcoal, such as those available for commercial retail use (i.e., charcoal used for grilling). PHMSA believes that adopting these IMO requirements would unnecessarily burden manufacturers with new testing, handling, and packaging requirements for consumer products, particularly given the lack of domestic incidents and unlikelihood that unpackaged bulk shipments of carbon materials are being transported to and from the U.S. PHMSA also disagrees with the IMDG Code prohibition on the use of UN Test N.4 to classify or exclude self-heating materials. PHMSA is not aware of any safety concerns or domestic safety incidents that justify the prohibition of the use of this test and believes that harmonizing the HMR with these particular sections of the IMDG Code would impose undue burdens for packaging and handling of carbon material without producing a corresponding safety benefit. Because shipments packaged in accordance with the IMDG Code are authorized for transport in the United States under Sec. 171.22, PHMSA does not anticipate any commercial or economic hardships will result from failing to adopt these requirements. Marking and labeling for battery powered vehicles--The 23rd revised edition of the UN Model Regulations and Amendment 42-24 of the IMDG Code adopted a new special provision, Special Provision 405, for battery powered vehicles (``UN3556, Vehicle, lithium ion battery powered,'' ``UN3557, Vehicle, lithium metal battery [[Page 6000]] powered,'' and ``UN3558, Vehicle, sodium ion battery powered''). Special Provision 405 provides an exception for battery powered vehicles from marking and labeling requirements when not fully enclosed by packagings, crates, or other means that prevent ready identification, thereby requiring marking and labeling when fully enclosed by packaging, crates, or other means that prevent ready identification. Special Provision 405 is similar to an existing Special Provision A87 in the ICAO Technical Instructions. Special Provision A87 applies to articles but was assigned to battery powered vehicles in the 2024-2025 edition. PHMSA is not proposing to adopt Special Provision 405 due to concerns raised in various international working groups regarding the necessity of the additional marking and labeling requirements. PHMSA believes that these requirements, which would require new marks and labels on a wide variety of popular consumer goods--e.g., lawn mowers, scooters, motorcycles, wheelchairs--should be subject to further evaluation. PHMSA seeks comments regarding the potential benefits of additional hazard communication requirements for battery powered vehicles transported in fully enclosed packagings. Non-removable specification markings--The 23rd revised edition of the UN Model Regulations and the 2025-2026 ICAO Technical Instructions states that UN specification markings must be placed on a non-removable component of the packaging. A transitional exception allows packagings to continue to be marked as required prior to the adoption of the new requirement until December 31, 2026, and for any packagings marked in such manner prior to January 1, 2027, to be permitted for continued use. PHMSA anticipates determining that the transitional exception is unnecessary as the HMR already includes such a requirement in Sec. 178.3(a), which states that packagings manufactured to a DOT specification or a UN standard must be marked with the proper specification marking on a non-removable component of the packaging. However, PHMSA seeks comments regarding the potential need for a similar transitional exception. Note that section 178.503(a) also applies the same requirement in Sec. 178.3(a) to the marking of performance-oriented packagings.\7\ --------------------------------------------------------------------------- \7\ This requirement was added in rulemaking HM-218. 65 FR 50450 (Aug. 18, 2000). --------------------------------------------------------------------------- V. Section-by-Section Review of NPRM Proposals The following is a section-by-section review of proposed amendments to harmonize the HMR with international regulations and standards. Part 171 Section 171.6 Section 171.6 of the HMR provides information on the OMB control numbers assigned to information collections under the Paperwork Reduction Act of 1995. The paragraph (b)(2) table lists the HMR sections associated with each OMB control number. As this NPRM proposes to add new information collection requirements to HMR, PHMSA proposes to revise this table to include the section references where this new information collection request is specified. See paragraph (K), under the ``Regulatory Analyses Notices'' section for additional details regarding new information collection requests. Section 171.7 Section 171.7 provides a listing of all consensus standards and regulations incorporated by reference into the HMR. PHMSA is proposing to add or revise the following references in Sec. 171.7 in this NPRM: \8\ --------------------------------------------------------------------------- \8\ All other standards that are set out as part of the regulatory text of Sec. 171.7(w) were previously approved for incorporation by reference and no changes are proposed. --------------------------------------------------------------------------- The 2023 edition of the American National Standards Institute (ANSI) N14.1-2023, Nuclear Materials--Uranium Hexafluoride-- Packagings for Transport in paragraph (d)(8), which is currently referenced in Sec. 173.420. This standard provides criteria for packagings used for transport of uranium hexafluoride (UF6). It includes specific information on design and fabrication requirements for the procurement of new packagings intended for the transportation of UF6 in quantities of 0.2205 lb. (0.1 kg) or more. It also defines the requirements for in-service inspections, cleanliness, and maintenance for packagings in service. Packagings currently in service and not specifically defined in this standard will continue to be authorized for use, provided they are used within their original design limitations, and are inspected, tested, and maintained to comply with the intent of this standard. This standard also includes requirements for cylinder loading, shipping, and valves, plugs, and valve protectors. PHMSA evaluated this updated standard and believes that the revisions provide an enhanced level of safety without imposing significant compliance burdens. This standard has a well-established and documented safety history, and the adoption of the 2023 edition is expected to maintain the safety standard currently achieved under the HMR. The 2023 edition of ANSI N14.1 is available for purchase on the ANSI website at: https://webstore.ansi.org/standards/pcc/ansin142023?source=blog . The 2025-2026 edition of the ICAO Technical Instructions in paragraph (t)(1) to replace the 2023-2024 edition, which is currently referenced in Sec. Sec. 171.8; 171.22-24; 172.101; 172.202; 172.401; 172.407; 172.512; 172.519; 172.602; 173.56; 173.320; 175.10, 175.33; and 178.3. The ICAO Technical Instructions specify detailed instructions and requirements for the international safe transport of dangerous goods (i.e., hazardous materials) by air. The 2025-2026 edition has been amended to align with the 23rd revised edition of the UN Model Regulations. Notable changes include new packing and stowage provisions, new and revised entries on its Dangerous Goods List, and editorial corrections. The 2025-2026 edition of the ICAO Technical Instructions is available for purchase on the ICAO website at https://store.icao.int/en/shop-by-areas/safety/dangerous-goods . The 2024 edition of the IMDG Code (Amendment 42-24) in paragraph (v)(2) to replace Incorporating Amendment 41-22, which is currently referenced in Sec. Sec. 171.22; 171.23; 171.25; 172.101; 172.202; 172.203; 172.401; 172.407; 172.502; 172.519; 172.602; 173.21; 173.56; 176.2; 176.5; 176.11; 176.27; 176.30; 176.83; 176.84; 176.140; 176.720; 176.906; 178.3; and 178.274. The IMDG Code is a unified international code that outlines standards and requirements for the transport of dangerous goods (i.e., hazardous materials) by sea (i.e., by vessel). Notable changes in Amendment 42-24 of the IMDG Code include new packing and stowage provisions, new and revised entries on its Dangerous Goods List, and editorial corrections. Distributors of the IMDG Code can be found on the IMO website at: www.imo.org/en/publications/Pages/Distributors-default.aspx . The following ISO documents to add new and updated standards for the specification, design, construction, testing, and use of gas cylinders in paragraph (w): --ISO 535:2014, Paper and board--Determination of water absorptiveness--Cobb method in paragraph (w)(1). PHMSA proposes to [[Page 6001]] remove the 1991 version of this document, ISO 535:1991, which is currently referenced in Sec. Sec. 178.707, 178.708, and 178.516, and to incorporate by reference the 2014 edition, ISO 535:2014 in its place. ISO 535:2014 specifies a method of determining the water absorptiveness of sized paper and board, including corrugated fiberboard, under standard conditions. This revised version contains changes to the introduction, annexes, and bibliography. The 23rd revised edition of the UN Model Regulations replaced the second edition with the third edition, and PHMSA proposes to mirror these changes for consistency. Replacing the 1991 version will allow references to updated annexed information and bibliographies, as well as for harmonization with other international standards, such as the 23rd revised edition of the UN Model Regulations, in which references to ISO 535:1991 have also been removed. --ISO 9809-4:2021, Gas cylinders--Design, construction and testing of refillable seamless steel gas cylinders and tubes--Part 4: Stainless steel cylinders with an R m value of less than 1 100 MPa in paragraph (w)(40). PHMSA proposes to incorporate by reference the second edition of this document, 9809-4:2021, and phase out the usage of the first edition, 9809-4:2014, by adding a sunset date of December 31, 2028.\9\ These documents are to be referenced in Sec. Sec. 178.71 and 178.75. ISO 9809-4:2021 specifies the minimum requirements for the materials, design, construction and workmanship, manufacturing processes, examinations and testing at time of manufacture for refillable, seamless, stainless steel gas cylinders with water capacities up to and including 150 L (i.e., ~40 gal.). As part of its regular periodic review process, ISO updated 9809-4:2014 and published the second edition, 9809-4:2021. The second edition includes changes to the requirements for inspection and testing, clarifications of drawings of the cylindrical parts of shells in Figure 3, and the addition of a new provision pertaining to shear stress calculations. --------------------------------------------------------------------------- \9\ The sunset dates proposed for adoption in this NPRM are consistent with the phaseout date adopted in the 23rd revised edition of UN Model Regulations. --------------------------------------------------------------------------- --ISO 11114-1:2020, Gas cylinders--Compatibility of cylinder and valve materials with gas contents Part 1: Metallic materials in paragraph (w)(51). PHMSA proposes to remove the second edition of this document, ISO 11114-1:2012, and the 2017 supplemental amendment, ISO 11114- 1:2012/Amd 1:2017, currently
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