PHMSA Revises DOT-39 Hazmat Cylinder Safety Alert

“DOT-39 cylinders exceeding 75 in.³ (1.23 L) should not contain liquefied flammable compressed cycloproprane, ethane, or ethylene, or liquefied petroleum gases. PHMSA advises against filling or transporting of these gases in DOT-39 cylinders when the cylinder’s internal volume exceeds 75 in.³ (1.23 L).”

See the revised PHMSA Safety Alert in the Federal Register.

The safety notice aims to address the risk posed by larger volumes of liquefied flammable compressed gases in cylinders. DOT-39 cylinders can have a volume of up to 1,526 in.³ (25 L) at a service pressure of 500 psig or less. When offering compressed gases at lower pressures in cylinders, shippers may be authorized to use cylinders with thinner walls—which increases the risk of puncture or corrosion in transit. 

The 75 in.³ volume limit has a history: In 1998, PHMSA—then known as the Research and Special Program Administration (RSPA)—proposed a rulemaking to limit all liquefied flammable compressed gases to 75 in.³ when shipped in DOT-39 cylinders. RSPA decided against this, but then inadvertently omitted the 75 in.³ limit for cyclopropane, ethane, ethylene, and liquefied petroleum gases from the Hazardous Materials Regulations (HMR) when finalizing the rule in 2002.

DOT tried to correct this error in 2016, when—in response to petitions from industry stakeholders—the Agency proposed a new rule to update the hazmat cylinder requirements and revise the cylinder filling requirements for cyclopropane, ethane, and ethylene in 49 CFR 173.304(a)(2). This rule has not yet been finalized.

Until a Final Rule is published, PHMSA is relying on its safety alert to help shippers and carriers avoid what the Agency (and many industry stakeholders) see as an unsafe shipping practice.
 

Don’t miss expert-led 49 CFR, IATA DGR, and IMDG Code training when it comes to your area in April. Build a step-by-step process for keeping your hazmat shipments in compliance with the latest requirements. Whether you ship hazmat every day or just once in a while, knowing your responsibilities is crucial to avoid rejection, costly customs delays, and DOT fines now as high as $77,114 per day, per violation.

This month, the Complete Multimodal Hazmat Shipper Certification Workshops will be presented in Chicago on May 2-5, and St. Louis on May 8-11.