{"operation":"document","citation":"25-0147","title":"Thompson Gas — Hazardous Materials Safety Interpretation","source_type":"guidance","agency":"Pipeline and Hazardous Materials Safety Administration","status":"guidance","official":true,"published_on":"2026-03-24","effective_on":null,"summary":"25-0147 response to Thompson Gas concerning 171.10, 171.8, 173.115.","machine_formats":{"json":"https://regulus.evalyn.ai/document/phmsa-interpretation-25-0147.json","markdown":"https://regulus.evalyn.ai/document/phmsa-interpretation-25-0147.md"},"app_url":"https://regulus.evalyn.ai/document/phmsa-interpretation-25-0147","source_url":"https://www.phmsa.dot.gov/standards-rulemaking/hazmat/interpretations/25-0147","body":"<<<PAGE 1>>>\n\n1200 New Jersey Avenue, SE\nWashington, DC 20590\nU.S. Department\nof Transportation\nPipeline and Hazardous\nMaterials Safety\nAdministration\nMarch 24, 2026\nGreg Miller\nLead Safety & Technical Trainer\nThompson Gas\n8895 Canyon River Ct.\nSparks, NV 89434\nReference No. 25-0147\nDear Mr. Miller:\nThis letter is in response to your October 27, 2025 letter and subsequent phone conversations\nwith my staff requesting clarification of the Hazardous Materials Regulations (HMR; 49 CFR\nParts 171-180) applicable to bulk packaging. Specifically, you ask whether a 120-gallon\nAmerican Society of Mechanical Engineers (ASME) propane container is bulk or non-bulk by\nwater weight as a receptacle for a gas, as specified by 49 CFR § 171.8.\nThe definition of a bulk packaging in § 171.8 states that a container with a water capacity greater\nthan 454kg (1000 pounds) as a receptacle for a gas, as defined in 49 CFR § 173.115, is a bulk\npackaging. If the information you provided in your calculation is accurate and the container is\nexactly 120 gallons with a 1000.8lb water weight capacity, then the container would be a bulk\npackaging. You also asked whether the container was bulk by kilograms instead of pounds.\nPHMSA notes that § 171.10(c)(2) provides conversion rates between the International System of\nUnits (SI) and U.S. standard measurements.\nI hope this information is helpful. Please contact us if we can be of further assistance.\nSincerely,\nAlexander Wolcott\nActing Chief, Regulatory Review and Reinvention Branch\nStandards and Rulemaking Division\n\n<<<PAGE 2>>>\n\nTHOMPSON\nJacobson, N.\n25-0147\n10/27/25\nMr. Shane Kelley\nDirector, Standards and Rulemaking Division\nU.S. DOT/PHMSA (PHH-10)\n1200 New Jersey Avenue, SE\nEast Building, 2nd Floor\nWashington, DC 20590\nSubject: Request for Letter of Interpretation - Classification of 120-Gallon ASME\nPropane Container Under 49 CFR §171.8\nDear Mr. Kelley:\nI am requesting a formal Letter of Interpretation regarding the classification of a 120-\ngallon ASME propane container when transported in commerce for stationary installation\nat a customer site. Specifically, I seek clarification on whether such a container should\nbe considered a bulk package or non-bulk package under 49 CFR §171.8.\nI have reviewed PHMSA Letter of Interpretation 19-0045, which provides guidance on\ndetermining bulk versus non-bulk packaging by referencing the 454 kg (~1,001 lb.)\nthreshold based on water capacity. My calculations are as follows:\n120 gallons x 8.34 lb/gallon (water weight) = 1,000.8 lb / 454.1 kg\nAssuming I am using the same number for the weight of water calculation that the\nHazardous Material Regulations uses, and because this total is just above 454 kg, the\nclassification appears to sit precisely on the regulatory threshold. The interpretation of\nthis borderline case is unclear to me. While the container appears to qualify as non-bulk\nby the pound conversion (under 1,001 lbs.), it technically exceeds the kilogram limit by\n0.1 kg, and I understand that when metric units appear, they are the regulatory standard.\nI would appreciate PHMSA's clarification on how this should be interpreted in practicespecifically,\nwhether such a 120-gallon ASME propane container should be treated as a\nbulk or non-bulk package for the purposes of the Hazardous Materials Regulations.\n\n<<<PAGE 3>>>\n\nThank you for your time and assistance. Please feel free to contact me if additional\ninformation is needed.\nRespectfully,\nGreg Miller\nLead Safety & Technical Trainer\nThompsonGas\ngmiller@thompsongas.com\n8895 Canyon River Ct.\nSparks, NV 89434\n253-256-2298","truncated":false,"body_characters":3587}