If you ship hazardous waste off-site, keep spent solvents in IBCs waiting on a manifest, or have crews running battery-powered equipment at a job site, this one's for you. On August 4, 2026, the Pipeline and Hazardous Materials Safety Administration (PHMSA) finalized 16 rules amending the Hazardous Materials Regulations (49 CFR Parts 107, 171–180) — mostly aimed at cutting outdated paperwork and adopting long-standing special permits directly into the regs. Almost all of it is effective September 3, 2026, with one earlier (August 19) and one later (December 2).

None of these are safety rollbacks. They're PHMSA cleaning up rules that had fallen behind how facilities actually operate. But "effective" means your procedures, training materials, and shipping paperwork should reflect them — not sit on the old special-permit language. Here's the short list of what matters most for California industrial and manufacturing sites.

1. Hazardous Waste Shippers: Watch the CERCLA List Change (HM-268E)

This is the one I'd flag first for my hazardous waste clients. PHMSA is eliminating the duplicate CERCLA hazardous substance and reportable quantity table it used to maintain in Appendix A to §172.101. Going forward, you consult EPA's list directly at 40 CFR §302.4. It's not a substantive change in what qualifies as a hazardous substance — it's PHMSA no longer keeping a second, occasionally outdated copy of EPA's list. Effective December 2, 2026 (PHMSA gave a 120-day delay specifically so facilities could update training and shipping systems). If your DOT paperwork process references the old §172.101 Appendix A table, that reference needs updating before December.

2. Residue-Only IBCs Can Skip the Full Shipping Paper Treatment (HM-268P)

For facilities that stage "empty" totes and IBCs before sending them for reconditioning or disposal — this legitimizes something a lot of sites have been doing informally. Steel, rigid-plastic, or composite IBCs (up to 550 gallons) holding no more than 0.3% residue by weight of a Packing Group II or III material can move without full shipping papers, placards, or UN ID markings, provided they're still marked/labeled, travel enclosed, go straight to an authorized servicing or disposal facility, and are accompanied by a simple "Residue IBC(s)" document. This was DOT Special Permit 21478 for over 20 years; now it's just the rule.

3. Bigger Lithium Battery Allowances Under Materials of Trade (HM-268C)

If your crews carry battery-powered tools, portable equipment, or backup batteries in a company vehicle, this one's practical. The Materials of Trade exception now allows up to 30 kg (66 lbs) per cell or battery and up to 500 kg (1,102 lbs) aggregate per vehicle — as long as the batteries passed UN 38.3 testing and are packaged or secured against short circuit, shifting, and accidental activation. Batteries installed in equipment aren't counted toward the aggregate cap at all. Worth reviewing with anyone managing field equipment fleets.

4. Drum and Tote Unloading Without Removal from the Vehicle (HM-268L)

Formerly Special Permits 12412 and 11646, now built into 49 CFR §177.834: certain Class 3, 5.1, 6.1, 8, and 9 materials in drums, IBCs, or DOT Spec 57 portable tanks can be discharged without pulling the container off the truck first — provided a qualified person is present, transfer equipment is inspected and pressure-tested, hoses aren't left connected during transport, and Class 3 materials are properly bonded and grounded. Relevant if your facility receives bulk chemical deliveries this way.

5. Paperwork Goes Digital (HM-268D, HM-268I, HM-268H)

Three separate rules quietly modernize recordkeeping: emergency response information can now be kept electronically instead of only on paper, PHMSA Certificates of Registration can be carried electronically in vehicles, and registration fee payments must now go through DOT's e-Commerce system instead of paper checks. None of this changes your underlying compliance obligations — it just changes the acceptable format. One catch worth noting: if you go electronic, you're still responsible for reliable access in the field. A dead phone battery isn't an excuse during an inspection, so build in a backup.

6. The Definition of "Aerosol" Just Got Broader (HM-268A)

This one's a bigger deal than it sounds if you manufacture, fill, or ship pressurized dispensing products. Under the old §171.8 definition, a product only qualified as an "aerosol" for HMR purposes if it was designed for the sole purpose of expelling a liquid, paste, or powder using a compressed or liquefied gas as the propellant. Gas-only products — dusters, gas-only spray cans, certain pressurized dispensers that release nothing but the gas itself — didn't meet that definition and had to be classified and shipped as fully regulated compressed gases instead, usually under an individual special permit.

Effective September 3, 2026, PHMSA amends §§171.8 and 171.23 so a qualifying non-refillable receptacle can be treated as an "aerosol" even when it dispenses only compressed, liquefied, or dissolved gas — no liquid, paste, or powder required. That aligns the U.S. definition with the UN Model Regulations, the IMDG Code, ICAO Technical Instructions, and European ADR rules, which have used the broader definition for years. In practice, qualifying gas-only products can now be classified and shipped as "Aerosols," UN1950, and can use limited-quantity exceptions where applicable — instead of being treated as a fully regulated compressed gas requiring its own special permit, dedicated shipping papers, and permit-specific training. The relief doesn't extend to air transportation, radioactive materials, international vessel shipments, or product on the outside of an overpack, and every other HMR packaging, marking, and labeling requirement still applies. If your facility ships anything filled with a gas-only propellant system, this is worth a classification review before September.

Also in the Package (Less Common, Still Worth Knowing)

• HM-268B: Limited-quantity marking can shrink to 25mm x 25mm when built into the shipping label itself.
• HM-268F: Packaging built under an expired manufacturing special permit can stay in service for its full usable life.
• HM-268G: Special permit renewals no longer need to be filed 60 days early — file any time before expiration and the current permit stays valid while PHMSA reviews it.
• HM-268J: Farm operations get a higher gross-receipts threshold ($825,000) before hazmat security-plan and training requirements kick in.
• HM-268K: Rail carriers lose an outdated reporting requirement to the AAR Bureau of Explosives; tank car spark-protection rules move to a performance-based standard.
• HM-268M / HM-268N: Larger allowances for A2L and GHS Category 1B refrigerants in refrigeration equipment shipped by highway or rail (20 kg and 5,000 lb thresholds, respectively).
• HM-268O: DOT 3A/3AA cylinder bundles get a 10-year requalification interval instead of 5, under specific conditions.

If you want a quick read on whether any of these 16 rules actually touch your operations — or you just want your hazmat shipping procedures cross-checked against the new §172.101/§302.4 reference — that's exactly the kind of thing I build into ongoing Compliance-as-a-Service. Reach out and we'll walk through it.

Rule changes like these are also a good trigger to get your team's DOT Hazmat training current. Plaid Safety offers onsite DOT Hazmat training tailored to your facility's actual shipping operations — not a generic slide deck — so your hazmat employees stay compliant with 49 CFR §172.704 and know exactly how changes like the ones above affect what's on their shipping papers. Let's get something on the calendar.

Source: PHMSA final rules published in the Federal Register, August 4, 2026 (Docket Nos. PHMSA-2025-0089 through PHMSA-2025-0104). This post is general information, not a substitute for reviewing the full Federal Register text against your specific operations.