HM-215R: PHMSA NPRM: International Harmonization

HM-215R: PHMSA NPRM: International Harmonization

On February 10, 2026, the U.S. Department of Transportation’s Pipeline and Hazardous Materials Safety Administration (PHMSA) published a new Notice of Proposed Rulemaking (NPRM) titled: “Hazardous Materials: Harmonization with International Standards.”

This long-awaited proposal would update the U.S. Hazardous Materials Regulations (HMR; 49 CFR Parts 171–180) to better align with the most recent international dangerous goods standards, including the UN Model Regulations, the ICAO Technical Instructions, the IMDG Code, and Canada’s TDG Regulations.

The goal is to improve regulatory consistency across transport modes, reduce conflicts for global shippers, and ensure the U.S. framework remains current with evolving hazards and technologies.

Comment Deadline

Have your say! Comments are due by April 13, 2026

Why Harmonization Rulemakings Matter

Let’s break down some of the highlights:

PHMSA harmonization rulemakings are some of the most significant updates to the HMR because they often include: new or revised Proper Shipping Names, changes to hazard classifications, updated packaging authorizations, adjustments to air transport limits, expanded or modified special provisions.

Battery-Related Updates

Battery-related changes are among the most impactful provisions in this proposal.

PHMSA is proposing new regulatory updates that reflect the rapid growth of battery-powered technologies, including new entries and transport alignment for sodium-ion batteries, clarifications tied to air shipment requirements, including state-of-charge limits and improved classification direction for battery-powered vehicles and equipment. These updates will require shippers to revisit classification workflows, packaging instructions, and training materials.

UN3536 Cargo Transport Units

The NPRM also addresses transport units shipped under UN3536, which covers large cargo transport units containing lithium batteries. PHMSA proposes clearer expectations for emergency response information, including better identification of battery type and appropriate mitigation guidance. This is an area where shippers may need to enhance documentation and response procedures beyond basic compliance with shipping paperwork.

Limited Quantity Expansion for Certain Gases

PHMSA proposes allowing several Division 2.2 non-flammable, non-toxic gases, including argon, helium, nitrogen, and carbon dioxide, to be shipped as limited quantities (up to 1000 mL per package) in modes other than air. For some distributors, this could reduce regulatory burden, but it will require careful review of packaging and modal restrictions.

Organic Peroxide Updates

Organic peroxides remain a high-risk class requiring strict control. The NPRM proposes updates to the organic peroxide classification table, including the addition of new formulations without prior approval and additional packaging authorizations for specific peroxide dispersions. Chemical manufacturers and specialty shippers should closely review these revisions for classification and packaging impacts.

TMAH Revisions

PHMSA proposes significant updates for tetramethylammonium hydroxide (TMAH) based on toxicity concerns and international harmonization. This may result in new shipping descriptions, revised hazard communication requirements, and updated packaging requirements, depending on the concentration and form.

Ammonium Nitrate Solutions

The proposal also includes new criteria for transporting certain hot, concentrated ammonium nitrate solutions, including conditions under which some mixtures may qualify for regulatory exceptions. This is especially relevant for shippers of fertilizers and industrial solutions that rely on precise chemical specifications for classification.

Hazardous Materials Table Updates

Like most harmonization rulemakings, PHMSA proposes numerous revisions to the Hazardous Materials Table (§172.101), including:

• New Proper Shipping Names
• Modified packing groups
• Updated special provisions
• Revised packaging authorizations
• Changes to air quantity limits

Final Thoughts

PHMSA’s 2026 long-awaited Harmonization NPRM is another major step in aligning U.S. hazardous materials transport requirements with international standards.

Need help navigating HM-215R? Contact ICC’s regulatory experts today. Do you have questions about hazardous materials? Our team of experts is just a call away for our customers at 855.734.5469 or send us an email, we’re happy to help.

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