PHMSA Issues Three Hazmat Deregulatory Rules; DOT Delays Disability Air-Travel Mandates

PHMSA adopts two special permits into standing regulations

The Pipeline and Hazardous Materials Safety Administration (PHMSA) has issued three final rules, all effective September 3, 2026, consolidating relief previously available only through special permit or exemption directly into the Hazardous Materials Regulations (HMR; 49 CFR parts 171–180).

The first rule adopts the provisions of DOT Special Permit 14175 by adding new paragraph (b)(2) to 49 CFR 180.209. The rule authorizes a 10-year requalification interval — rather than the existing five-year interval — when either ultrasonic examination (UE) testing or hydrostatic testing with visual inspection is used for DOT specification 3A and 3AA cylinders in flammable and non-flammable, nonpoisonous gas service. PHMSA states the action "reflects advances in testing technology and will relieve stakeholders of the burden of performing more frequent cylinder requalification." The agency explains it is also acting in response to commenter feedback and as part of its ongoing review of special permits with proven safety records. Effective 30 days after publication, holders of DOT SP 14175 will no longer need a special permit to requalify the covered cylinder bundles using UE. The rule amends 49 CFR 180.

The second rule adopts the provisions of DOT Special Permit 21478 by revising 49 CFR 173.29 to add a new subparagraph (d), allowing "empty" intermediate bulk containers (IBCs) that contain only the residue of a hazardous material to be transported without shipping papers, placards, and United Nations (UN) identification numbers. PHMSA explains this extends to IBCs the same type of relief already permitted for empty non-bulk packaging under 49 CFR 173.29(c), and notes it "has authorized this widely-utilized special permit for years with a proven track record for safety." The rule requires that a document — in paper or electronic form — accompany the IBCs, denoting the phrase "Residue IBC(s)" and indicating the number of IBCs containing hazardous materials for each Class or Division of material on the transport vehicle. Conforming revisions are made to 49 CFR 172.331, 172.504, and 172.514, including an amendment to 172.514 clarifying that IBCs shipped under the empty packaging exception are not subject to placarding. Effective 30 days after publication, holders of DOT SP 21478 will no longer need a special permit to transport covered empty IBCs.

Lithium battery transport limits expanded for trades companies

The third PHMSA final rule modernizes the Materials of Trade (MOT) exception under 49 CFR 173.6 by increasing the maximum allowable quantities of lithium batteries that can be transported as MOTs. The rule, also effective September 3, 2026, is directed at domestic companies in sectors including construction, landscaping, mowing, tree service, food service, and entertainment.

PHMSA explains that the HMR currently limits the aggregate gross weight of materials of trade — other than certain diluted mixtures of Class 9 materials — in a motor vehicle to 200 kg (440 pounds). The revision increases allowances for lithium batteries by authorizing up to 30 kg (66 pounds) per battery, a 500 kg (1,102 pounds) gross vehicle limit, and no limit for batteries installed in equipment. The agency states the rule includes safety provisions to prevent short circuits, shifting damage, and accidental activation. PHMSA states the action "will reduce regulatory burdens for companies that transport batteries and battery-powered equipment in support of a trade without any compromise in safety" and that it advances the goals of multiple Executive Orders while providing annualized cost savings to American businesses. The rule amends 49 CFR 173.

DOT extends enforcement discretion on disability air-travel rules to April 30, 2027

The Department of Transportation (DOT) is extending and expanding its enforcement discretion on several provisions governing air travel for passengers with disabilities. As of August 4, 2026, enforcement of four provisions of the "Ensuring Safe Accommodations for Air Travelers With Disabilities Using Wheelchairs" final rule (Wheelchair Rule I) — covering airline liability for mishandled wheelchairs (14 CFR 382.130(a)), refresher training frequency (14 CFR 382.141(a)(6)), pre-departure notifications (14 CFR 382.125(e)), and fare difference reimbursements (14 CFR 382.132) — is extended from December 31, 2026 to April 30, 2027.

DOT is also expanding enforcement discretion to include the 12-month hands-on training mandate for flight attendants found in 14 CFR 382.63(h)(1) under the "Accessible Lavatories on Single-Aisle Aircraft" final rule (Accessible Lavatory Rule), originally issued on August 1, 2023. That provision, which requires airlines to train flight attendants to proficiency on an annual basis to assist qualified individuals with disabilities in using the on-board wheelchair (OBW), was scheduled to become effective on October 2, 2026.

DOT states the extension is "necessary to allow sufficient time for the Department to review and analyze public comments, and to make final determinations regarding the content of the final rule." The agency had previously stated the earliest it expected to reach a decision was December 31, 2026, but now anticipates that date will be April 30, 2027. Both sets of provisions will be formally addressed in an upcoming rulemaking titled "Airline Obligations to Accommodate Air Travelers with Disabilities Using Wheelchairs" (Wheelchair Rule II). DOT notes that the exercise of enforcement discretion "does not prejudge the outcome of the new rulemaking" and does not affect enforcement of other requirements in the Accessible Lavatory Rule.

FAA mandates ELT inspection for Diamond Aircraft DA20-C1 airplanes

The Federal Aviation Administration (FAA) is adopting a new airworthiness directive (AD) for certain Diamond Aircraft Industries Inc. (DAI) Model DA20-C1 airplanes, effective September 8, 2026. The AD was prompted by a report of an Artex ELT 1000 emergency locator transmitter failing to activate due to a missing jumper wire. The FAA explains that further investigation by the manufacturer revealed that some Artex ELT 1000 units might not have a jumper wire between D-sub pins 5 and 12, which "could prevent the ELT beacon from being activated by the internal G-Switch and the aural alert buzzer from being activated in the event of an accident."

The AD requires a continuity inspection of the D-sub connector of the Artex ELT 1000 and, if necessary, corrective actions, as detailed in Diamond Aircraft Industries Mandatory Service Bulletin No. DAC1-25-05 Rev. 1, dated July 19, 2024. The FAA estimates this AD affects 365 airplanes of U.S. registry. The agency estimates compliance costs at 1 work-hour at $85 per hour, for a cost per product of $85 and a total cost on U.S. operators of $31,025. If the jumper wire must be installed, the FAA estimates an on-condition cost of 1 work-hour at $85 per hour plus $3 in parts, for a cost per product of $88. The AD was prompted by Transport Canada AD CF-2026-03, dated January 21, 2026.

What to watch

• September 3, 2026: All three PHMSA final rules take effect — SP 14175 cylinder requalification, SP 21478 empty IBC transport, and the expanded MOT lithium battery limits.
• September 8, 2026: FAA airworthiness directive for DAI DA20-C1 ELT inspection takes effect.
• October 2, 2026 (now under enforcement discretion pause): The Accessible Lavatory Rule's annual hands-on OBW training requirement for flight attendants was previously scheduled to become effective on this date but will not be enforced until at least April 30, 2027.
• April 30, 2027: DOT's enforcement discretion on both the four Wheelchair Rule I provisions and the Accessible Lavatory Rule training mandate expires; DOT's Wheelchair Rule II final determination is expected no earlier than this date.

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