Proposal aligns hazmat regs with international standards
The Pipeline and Hazardous Materials Safety Administration (PHMSA) has issued its proposed HM 215R rule, a broad update intended to align the Hazardous Materials Regulations (HMR) with the newest international standards. Published February 10, 2026, the proposal is open for public comment through April 13, 2026. It introduces extensive changes affecting classifications, proper shipping names, packaging rules, and modal requirements.
By updating U.S. regulations to reflect current global practices while declining to adopt international provisions deemed unnecessary, PHMSA intends to minimize compliance burdens, eliminate conflicting requirements, strengthen emergency response clarity, and support smooth movement of hazardous materials across borders.
Major proposed changes
Below are the most notable updates hazmat professionals should prepare for.
- Incorporations by reference
PHMSA proposes adopting updated editions of the ICAO Technical Instructions, IMDG Code, UN Model Regulations, Transport Canada TDG Regulations, and multiple ISO gas cylinder standards. - Hazardous materials table (HMT) revisions
The rule updates numerous entries, adding new proper shipping names, revising hazard classes, modifying packing groups, and removing outdated entries. - Expanded limited quantity relief for compressed gases
For highway, rail, and vessel transportation, limited quantity authorizations expand to 1000 mL (34 fl. oz.) for argon, carbon dioxide, helium, and nitrogen, reflecting incorporation from both international regulations and prior U.S. special permits. - Sodium ion batteries
Reflecting rapid commercialization of sodium‑ion technology, PHMSA proposes new HMT entries (UN3551, UN3552) with requirements modeled closely on those for lithium‑ion batteries. This includes packaging standards, special provisions, vessel‑stowage rules, and certain air‑transport limitations. - TMAH reclassification
Based on new incident and toxicity data for Tetramethylammonium hydroxide (TMAH), PHMSA proposes:- A new entry for ≥25 percent aqueous solutions (UN3560),
- Reclassification of solids and stronger concentrations to Division 6.1 (toxic) with Class 8 subsidiary risk,
- Concentration based proper shipping names, and
- New special provisions clarifying appropriate descriptions and providing transition time for hazard communication updates.
- New formulations for organic peroxides
Several new peroxide formulations are added to the Organic Peroxide Table, allowing them to move without prior approval, and new packaging options are authorized for specific formulations, which is consistent with UN changes.
- Fire suppressant dispersing devices
Growing use in industries like energy storage, server rooms, and transport sectors has prompted new rules for fire suppressant dispersing devices, including:- New entries for UN0514 (1.4S) and UN3559 (Class 9),
- New classification and packaging criteria in §173.169, and
- Requirements for testing, activation safeguards, and performance limits (e.g., surface temperature <200°C when activated in packaging).
- Lithium & sodium ion batteries
To address thermal runaway risks in lithium and sodium ion batteries, PHMSA proposes:- A 30 percent state of charge limit for certain lithium and sodium ion batteries transported by air, including those installed in vehicles,
- Extended requirements for prototypes and low production run batteries, and
- Enhanced emergency response information for UN3536, battery energy storage systems.
- Gallium in manufactured articles
New entry UN3554 provides clarity for gallium bearing articles, recognizing gallium’s role as a mercury alternative. New packaging and exceptions mirror international requirements.
- Marine pollutants list additions
To align with IMDG Code updates, PHMSA proposes adding the following substances to the list of marine pollutants:- Isopropenylbenzene,
- 2-phenylpropene, and
- Cobalt dihydroxide powder (>10 percent respirable particles).
International updates PHMSA declined to adopt
PHMSA rejected several proposed international changes, including:
- More stringent IMDG requirements for carbon/charcoal,
- New battery powered vehicle marking/labeling requirements, and
- Prohibitions on use of UN Test N.4 for carbon classification.
Submitting comments
Stakeholders may file comments by April 13, 2026, via:
- www.regulations.gov (Docket PHMSA 2023 0111)
- Fax: 202-493-2251
- Mail/hand delivery to DOT Docket Operations in Washington, DC
Key to remember: HM 215R harmonization rule aligns the HMR with international dangerous goods standards. Hazmat professionals should review the proposed rule and provide feedback before the comment window closes.






















































