# Thompson Gas — Hazardous Materials Safety Interpretation **Citation:** 25-0147 **Type / status:** guidance / guidance **Agency:** Pipeline and Hazardous Materials Safety Administration **Effective:** Not stated **Published:** 2026-03-24 25-0147 response to Thompson Gas concerning 171.10, 171.8, 173.115. ## Document text <<>> 1200 New Jersey Avenue, SE Washington, DC 20590 U.S. Department of Transportation Pipeline and Hazardous Materials Safety Administration March 24, 2026 Greg Miller Lead Safety & Technical Trainer Thompson Gas 8895 Canyon River Ct. Sparks, NV 89434 Reference No. 25-0147 Dear Mr. Miller: This letter is in response to your October 27, 2025 letter and subsequent phone conversations with my staff requesting clarification of the Hazardous Materials Regulations (HMR; 49 CFR Parts 171-180) applicable to bulk packaging. Specifically, you ask whether a 120-gallon American Society of Mechanical Engineers (ASME) propane container is bulk or non-bulk by water weight as a receptacle for a gas, as specified by 49 CFR § 171.8. The definition of a bulk packaging in § 171.8 states that a container with a water capacity greater than 454kg (1000 pounds) as a receptacle for a gas, as defined in 49 CFR § 173.115, is a bulk packaging. If the information you provided in your calculation is accurate and the container is exactly 120 gallons with a 1000.8lb water weight capacity, then the container would be a bulk packaging. You also asked whether the container was bulk by kilograms instead of pounds. PHMSA notes that § 171.10(c)(2) provides conversion rates between the International System of Units (SI) and U.S. standard measurements. I hope this information is helpful. Please contact us if we can be of further assistance. Sincerely, Alexander Wolcott Acting Chief, Regulatory Review and Reinvention Branch Standards and Rulemaking Division <<>> THOMPSON Jacobson, N. 25-0147 10/27/25 Mr. Shane Kelley Director, Standards and Rulemaking Division U.S. DOT/PHMSA (PHH-10) 1200 New Jersey Avenue, SE East Building, 2nd Floor Washington, DC 20590 Subject: Request for Letter of Interpretation - Classification of 120-Gallon ASME Propane Container Under 49 CFR §171.8 Dear Mr. Kelley: I am requesting a formal Letter of Interpretation regarding the classification of a 120- gallon ASME propane container when transported in commerce for stationary installation at a customer site. Specifically, I seek clarification on whether such a container should be considered a bulk package or non-bulk package under 49 CFR §171.8. I have reviewed PHMSA Letter of Interpretation 19-0045, which provides guidance on determining bulk versus non-bulk packaging by referencing the 454 kg (~1,001 lb.) threshold based on water capacity. My calculations are as follows: 120 gallons x 8.34 lb/gallon (water weight) = 1,000.8 lb / 454.1 kg Assuming I am using the same number for the weight of water calculation that the Hazardous Material Regulations uses, and because this total is just above 454 kg, the classification appears to sit precisely on the regulatory threshold. The interpretation of this borderline case is unclear to me. While the container appears to qualify as non-bulk by the pound conversion (under 1,001 lbs.), it technically exceeds the kilogram limit by 0.1 kg, and I understand that when metric units appear, they are the regulatory standard. I would appreciate PHMSA's clarification on how this should be interpreted in practicespecifically, whether such a 120-gallon ASME propane container should be treated as a bulk or non-bulk package for the purposes of the Hazardous Materials Regulations. <<>> Thank you for your time and assistance. Please feel free to contact me if additional information is needed. Respectfully, Greg Miller Lead Safety & Technical Trainer ThompsonGas gmiller@thompsongas.com 8895 Canyon River Ct. Sparks, NV 89434 253-256-2298 ## Provenance - Official: Yes - Source: - Source ID: `phmsa` - SHA-256: `9b4f1431289cd344b76146c2633f66da06189d4cb7f3ad34345142686db1c8c5` - Retrieved: 2026-08-20T00:59:31.977Z - Exported: 2026-08-23T01:04:50.890Z - Document slug: `phmsa-interpretation-25-0147` ### Source metadata ```json { "materialSubtype": "interpretation", "interpretationArea": "hazardous_materials", "representation": "full_text_from_official_pdf", "companies": [ "Thompson Gas" ], "individuals": [ "Greg Miller" ], "refIds": [ "25-0147" ], "catalogDates": [ "2026-03-24" ], "catalogParts": [ 171, 173 ], "catalogRowCount": 3, "sourceRecordUrls": [ "https://www.phmsa.dot.gov/node/82926" ], "linkedAttachmentUrls": [], "unavailableResponseUrls": [], "duplicateRepresentationUrls": [], "citedSections": [ "171.10", "171.10(c)(2)", "171.8", "173.115" ], "catalogPageUrls": [ "https://www.phmsa.dot.gov/regulations/title49/section/17110", "https://www.phmsa.dot.gov/regulations/title49/section/1718", "https://www.phmsa.dot.gov/regulations/title49/section/173115" ], "pdfUrls": [ "https://www.phmsa.dot.gov/sites/phmsa.dot.gov/files/2026-03/25-0147.pdf" ], "representations": [ { "viewUrl": "https://www.phmsa.dot.gov/standards-rulemaking/hazmat/interpretations/25-0147", "detailUrl": "https://www.phmsa.dot.gov/standards-rulemaking/hazmat/interpretations/25-0147", "detailHtmlPath": "data/sources/phmsa-interpretations/detail-pages/25-0147-958c3780.html", "pdfUrl": "https://www.phmsa.dot.gov/sites/phmsa.dot.gov/files/2026-03/25-0147.pdf", "pdfArtifactPath": "data/sources/phmsa-interpretations/25-0147-3cfdf5411a.pdf", "pdfArtifactSha256": "e1c0a255492d40b06fe58f7879df8f6b0b0a866c909786497ec59b534d6c00c4", "extractedTextPath": "data/sources/phmsa-interpretations/25-0147-3cfdf5411a.v2.txt", "extractedTextSha256": "256e12cc9c31bd9b7f12ed0fc74aedded25d375cb2210adc8e71eabc9468b17c", "pageCount": 3, "extractionVersion": 2 } ], "caveat": "Interpretations apply regulations to the facts presented and do not create independently enforceable requirements.", "jurisdiction": "US" } ```