AGENCY:

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

ACTION:

Final rule.

SUMMARY:

To improve efficiency and eliminate redundancy, this final rule streamlines the Hazardous Materials Regulations by modifying how hazardous substances are listed. Instead of maintaining a duplicative list, the regulations will now rely on the authoritative, comprehensive list already maintained by the U.S. Environmental Protection Agency.

DATES:

This final rule is effective December 2, 2026.

FOR FURTHER INFORMATION CONTACT:

Tony Horne, Standards and Rulemaking Division, Pipeline and Hazardous Materials Safety Administration (PHMSA), 1200 New Jersey Avenue SE, Washington, DC 20590, 202-366-8553, tony.horne@dot.gov.

I. PHMSA Action

A. What action is PHMSA taking in this final rule?

PHMSA is modifying how hazardous substances and their reportable quantities are listed within the Hazardous Materials Regulations (HMR). Specifically, rather than maintaining a duplicative list found in Tables 1 and 2 to Appendix A of 49 CFR 172.101 that must be periodically ( printed page 49306) revised for consistency with the U.S. Environmental Protection Agency (EPA) list found at 40 CFR 302.4, PHMSA is amending Appendix A to reference the EPA list directly. In addition, PHMSA is revising the definitions of “hazardous substance” and “reportable quantity (RQ)” to reference the EPA list in a seamless manner. Finally, PHMSA is making a conforming revision to the requirements for empty packagings to reflect the newly modified structure of Appendix A.

B. Does this action apply to me?

Effective 120 days after publication of this final rule, persons offering for transportation and transporting materials that may be subject to hazardous substance requirements in the HMR must refer to the EPA regulations at 40 CFR 302.4 for the list of regulated hazardous substances and their reportable quantities. Importantly, because this action simply modifies how the list is referenced within the Code of Federal Regulations, it does not functionally change whether a material is classified as a hazardous substance.

C. Why is PHMSA taking this action?

To enhance government efficiency and eliminate regulatory redundancy, this final rule streamlines the HMR by modifying how hazardous substances are listed. Importantly, this action does not delete the entire Hazardous Materials Table (HMT); rather, it solely amends the HMR to modify Appendix A to the HMT—which currently houses a redundant list of hazardous substances and their reportable quantities (RQs)—by directing compliance to the comprehensive list already maintained by the U.S. Environmental Protection Agency (EPA) in a Table at 40 CFR 302.4. As a matter of sensible regulatory oversight, this alignment avoids the costly confusion of navigating out-of-sync regulations. In the past, stakeholders have expressed confusion whether a hazardous substance that is listed by EPA—but not yet listed by PHMSA via a rulemaking—is subject to transportation requirements under the HMR for hazardous substances.^[1] It also ensures the regulated community can avoid the inverse; specifically, a circumstance where an entity incurs the unnecessary expense of continuing to transport a substance as a hazardous material simply because a separate DOT list lagged behind an EPA de-listing or an increase in the RQ.

In addition, this action conserves scarce government resources by eliminating the need for periodic, limited-purpose rulemakings previously required to keep the HMR's list and RQs consistent with EPA updates. Furthermore, directly referencing the EPA's list reflects the reality that treating these designated substances as hazardous materials in transport has been a statutory requirement all along, meaning that this rule should result in no real-world change to how regulated entities are operating.^[2]

II. Discussion of Comments Received in Response to the Notice of Proposed Rulemaking

PHMSA published a notice of proposed rulemaking (NPRM), cited as HM-268E, to gather feedback on revising the HMR to streamline the listing of hazardous substances and reportable quantities by referring directly to the source list found in EPA regulations.^[3] Please refer to the NPRM for background and discussion of the proposed change.

The following table alphabetically lists commenters to the NPRM:

PHMSA received mixed support for the proposed changes among the eight sets of comments submitted in response to the NPRM. Some commenters supported the proposed changes because eliminating the redundant list is a practical way to ensure consistency in how hazardous substances are regulated in transportation. For instance, COSTHA noted that the revision removes duplication that has historically caused inconsistencies between PHMSA's list and EPA's authoritative list, thereby creating confusion for shippers, carriers, and enforcement personnel.

PHMSA received varied feedback on the proposed changes and appreciates the input from all commenters. To enhance consistency, efficiency, and clarity, the agency is proceeding with the revisions to address the issue of redundant regulatory text. Addressing this duplication aligns PHMSA's requirements with the EPA's authoritative list and resolves historical inconsistencies that have caused unnecessary and avoidable confusion for shippers, carriers, and enforcement personnel.

However, some commenters expressed concerns with the proposals. PHMSA responds to those concerns as follows:

A. Introducing Potential Burden From a Second Set of Regulations

ACD, CVSA, DGAC, Mr. Rex Railsback, and Mr. William Forbes shared concerns regarding additional economic burdens associated with purchasing new regulatory texts and associated retraining. CVSA stated that commercial motor vehicle inspectors who conduct hazardous materials inspections must have ready access to information that is reliable, and that the proposed change may require inspectors to navigate a second set of unfamiliar regulations. DGAC believed that the proposed change would require trainers to provide print copies of, or excerpts from, the relevant 40 CFR provisions to ( printed page 49307) every affected hazmat employee, and that enforcement officers would have to maintain copies as well. Mr. Railsback stated that the relevant 40 CFR provisions are not available via the electronic oCFR (which PHMSA notes is an unofficial source provided as a courtesy on the PHMSA website), and that PHMSA does not make the relevant 40 CFR provisions available in print without purchasing additional text.

PHMSA respectfully disagrees and asserts this change will not impose any economic burdens nor create any accessibility issues. PHMSA does not make any resources available in print. Instead, the Office of the Federal Register maintains a web-based version of the entire CFR, to include relevant 40 CFR provisions, that is available for free via the electronic CFR (eCFR), and it is updated in real-time.^[4] The relevant portions of 40 CFR can also be downloaded on an electronic device to use in areas with limited internet or cellular connectivity. Therefore, because the entire CFR is available free online, and it is updated on a daily basis, PHMSA does not believe this rule will be a barrier or create any burdens for trainers, hazmat employees, or enforcement personnel.^[5]

B. Training

DGAC and Infotrac, Inc. stated the proposed changes would necessitate additional training on different sets of regulations that hazmat employees normally do not receive. DGAC further argued that:

[A]n inordinately large number of individuals will be impacted. In addition, because the determination of whether or not a material is a hazardous substance under the HMR is based on whether the quantity per package equals or exceeds the listed reportable quantity, the proposed change would require numerous additional individuals who package materials to require training in the use of 40 CFR in addition to their existing required training on the HMR.

DGAC concluded that the need for additional training stems from the prospect of materials being added to or removed from the list of hazardous substances and persons having to monitor the Federal Register for changes to relevant 40 CFR provisions.

PHMSA acknowledges the concerns raised by these commenters but respectfully disagrees. First, this action does not delete the Hazardous Materials Table (HMT) itself; rather, it solely modifies Appendix A. In addition, those persons using the free, online eCFR will be able to access the relevant 40 CFR provisions directly via a hyperlink.

More importantly, this rule imposes no substantive, real-world changes to the applicability of the HMR to hazardous substances. A hazardous substance is regulated under the HMR if it is listed in the relevant 40 CFR provisions and it equals or exceeds the (listed) RQ in a package.^[6] Whether the list resides in the HMR or in relevant 40 CFR provisions has no bearing on its applicability to hazardous substances. The EPA list remains the authoritative list and resides in 40 CFR 302.4. PHMSA now refers stakeholders to the authoritative list located in relevant 40 CFR provisions. The eCFR provides hyperlinks anytime a portion of the CFR is cited in the regulatory text, making it readily accessible by way of the HMR.

Moreover, part of the scope of HMR training is providing assurances that a hazmat employee has familiarity with the general provisions of the HMR and can recognize and identify the presence of hazardous materials. Persons in the business of transporting hazardous materials that are hazardous substances subject to HMR requirements should already be familiar with the applicable requirements. Such persons should also be aware that changes can be made to the list—including removals, additions, or changes to RQs. In addition, PHMSA believes this general awareness or familiarization training should already be captured under the standard recurrent training expected of hazmat employers.

C. Preserving Appendix B

COSTHA and DGAC recommend maintaining Appendix B as written and, instead of converting the Appendix B list of marine pollutant to Appendix A as proposed, they suggest revising Appendix A by providing a direct reference to 40 CFR 302.4 for the list of hazardous substances and their reportable quantities. Specifically, COSTHA noted that “keeping the . . . placeholder and including a reference link would provide better continuity and make the regulation easier to navigate,” and that “while referencing two regulations adds an additional step for compliance, it does improve long-term efficiency and accuracy of these applicable regulatory updates.” Further, DGAC reasoned that adopting the changes to the 49 CFR 172.101 appendixes would cause confusion and potentially result in frustration or denial of shipments.

PHMSA agrees with the commenters. Rather than adopting the proposed changes to 49 CFR 172.101 and to avoid introducing confusion from relabeling appendices, in this final rule PHMSA will maintain the Appendix B to § 172.101—List of Marine Pollutants as written and instead revise Appendix A to reference 40 CFR 302.4.

D. Delayed Effective Date

IHMM asked PHMSA to consider a delayed effective date to allow entities to update systems and training materials consistent with the transition from an HMR list at 49 CFR to the EPA list at 40 CFR.

In consideration of the comments about training and familiarity with alternate regulatory text, PHMSA agrees with IHMM and is providing a delayed effective date to allow time to adjust. This final rule has an effective date 120 days from the date of publication of the final rule when Appendix A to 49 CFR 172.101 will refer to the list of hazardous substances in 40 CFR 302.4. PHMSA's outreach program will make efforts to ensure stakeholders are aware of this change and are educated on how to navigate from the relevant provisions 49 CFR to those in 40 CFR.

III. Regulatory Analysis and Notices

A. Legal Authority

This final rule is published under the authority of the Secretary of Transportation as set forth in the Federal Hazardous Materials Transportation Laws (49 U.S.C. 5101 et seq.) and delegated to the PHMSA Administrator pursuant to 49 CFR 1.97.

B. Executive Order 12866; Regulatory Planning and Review

Executive Order (E.O.) 12866 ( Regulatory Planning and Review), as implemented by 49 CFR part 5, subpart B, 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.” ^[7] 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 ( printed page 49308) 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.” Pursuant to 49 CFR part 5, subpart B, 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. In addition, 49 CFR part 5, subpart B specifies that regulations should generally “not be issued unless their benefits are expected to exceed their costs.”

E.O. 12866 and 49 CFR part 5, subpart B 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 final rule is not a significant regulatory action pursuant to E.O. 12866 and has not been designated as a “major rule” as defined by the Congressional Review Act (5 U.S.C. 801 et seq.).

PHMSA has complied with the requirements in E.O. 12866 as implemented by 49 CFR part 5, subpart B and determined this final rule will result in cost savings to the government by streamlining regulations and eliminating redundancy. The rule will also benefit the regulated public by clarifying applicability and reducing confusion.

C. Executive Orders 14192 and 14219

PHMSA has determined that this final rule is an E.O. 14192 ( Unleashing Prosperity Through Deregulation ) deregulatory action.^[8] PHMSA finds the total costs of the rule on the regulated community will be less than zero. This final rule does not implicate any of the factors identified in section 2(a) of E.O. 14219 ( Ensuring Lawful Governance ) indicative of a regulation that is “unlawful . . . [or] that undermine[s] the national interest.” ^[9]

D. Energy-Related Executive Orders 13211, 14154, and 14156

PHMSA has analyzed this final rule in accordance with the principles and criteria contained in E.O. 14156 ( Declaring a National Energy Emergency) and E.O. 14154 ( Unleashing American Energy ).^[10] The President has declared a national emergency to address America's inadequate energy development production, transportation, refining, and generation capacity and asserts a Federal policy to unleash American energy by ensuring 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. PHMSA finds this final rule to be consistent with E.O. 14156 and E.O. 14154 because it will not hinder or unduly burden the transportation or production of energy or energy-related products.

In addition, this final rule is not a “significant energy action” under E.O. 13211 ( Actions Concerning Regulations That Significantly Affect Energy Supply, Distribution, or Use ), which requires Federal agencies to prepare a Statement of Energy Effects for any “significant energy action.” ^[11] Because this final rule is not a significant action under E.O. 12866, it will not have a significant adverse effect on supply, distribution, or energy use; accordingly, OIRA has not designated this final rule as a significant energy action.

E. Executive Order 13132: Federalism

PHMSA analyzed this final rule in accordance with the principles and criteria contained in E.O. 13132 ( Federalism) and the Presidential Memorandum ( Preemption) published in the Federal Register on May 22, 2009.^[12] 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;

(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 final rule addresses items covered in Paragraph 1 above and would preempt State, local, and Tribal requirements not meeting the “substantively the same” standard. Though the final 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 final 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. 601 et seq.) requires Federal agencies to conduct a Final Regulatory Flexibility Analysis (RFA) for a final rule that has been subject to notice-and-comment rulemaking under the APA unless the agency head certifies that the final rule will not have a significant economic impact on a substantial number of small entities. E.O. 13272 ( Proper Consideration of Small Entities in Agency Rulemaking ) obliges agencies to establish procedures promoting compliance with the Regulatory Flexibility Act.^[13] DOT posts information on a dedicated web page to help small businesses understand and navigate Federal regulatory processes.^[14] This final rule was developed in accordance with E.O. 13272 and DOT implementing guidance to ensure compliance with the Regulatory Flexibility Act. The final rule will reduce burdens. Therefore, PHMSA certifies the final rule does not have a significant impact on a substantial number of small entities.

( printed page 49309)

G. Unfunded Mandates Reform Act of 1995

The Unfunded Mandates Reform Act (UMRA, 2 U.S.C. 1501 et 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 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 final 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

PHMSA has analyzed this rule pursuant to the National Environmental Policy Act (NEPA; 42 U.S.C. 4321 et seq.) and has determined it is categorically excluded under 23 CFR 771.117(c)(20), which applies to the promulgation of rules, regulations, and directives. Under Section 9 of DOT Order 5610.1D, PHMSA may apply a categorical exclusion (CE) established in another Operating Administration's procedures. PHMSA followed the requirements outlined in DOT Order 5610.1D to apply the Federal Highway Administration's CE to this deregulatory action. PHMSA has determined no unusual circumstances are present under 23 CFR 771.117(b). PHMSA's Categorical Exclusion Determination memo for this action is available on PHMSA's website.^[15]

I. Executive Order 13175

PHMSA analyzed this final rule according to the principles and criteria in E.O. 13175 ( Consultation and Coordination with Indian Tribal Governments) and DOT Order 5301.1A ( Department of Transportation Tribal Consultation Policies and Procedures ).^[16] 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 final rule and determined that it will not significantly or uniquely affect Tribal communities or Indian Tribal governments. The rulemaking's regulatory amendments have a broad, national scope; therefore, this final rule will not significantly or uniquely affect Tribal communities, much less impose substantial compliance costs on 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. 3501 et 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 will not create, amend, or rescind any existing information collections.

K. Executive Order 13609 and International Trade Analysis

E.O. 13609 ( Promoting International Regulatory Cooperation ) 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.^[17] 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 final rule and has determined that its regulatory amendments will not cause unnecessary obstacles to foreign trade.

L. Cybersecurity and Executive Order 14028

E.O. 14028 ( Improving the Nation's Cybersecurity ) directed the Federal Government to improve its efforts to identify, to deter, and to respond to “persistent and increasingly sophisticated malicious cyber campaigns.” ^[18] PHMSA has considered the effects of the final rule and has determined that its regulatory amendments would not materially affect the cybersecurity risk profile for affected entities.

M. Privacy Act Statement

In accordance with 5 U.S.C. 553(c), DOT solicits comments from the public to inform its rulemaking process better. DOT posts these comments, without edit, including any personal information the commenter provides, to 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. DOT's complete Privacy Act Statement in the Federal Register published on April 11, 2000, and may be viewed on DOT's website at https://www.dot.gov/​privacy.

In consideration of the foregoing, PHMSA amends 49 CFR Chapter I as follows: