# The Hartford Steam Boiler Inspection and Insurance Co. — Hazardous Materials Safety Interpretation **Citation:** 19-0051 **Type / status:** guidance / guidance **Agency:** Pipeline and Hazardous Materials Safety Administration **Effective:** Not stated **Published:** 2019-10-15 19-0051 response to The Hartford Steam Boiler Inspection and Insurance Co. concerning 178.46. ## Document text <<>> 0 U.S. Department of Transportation Pipeline and Hazardous Materials Safety Administration 1200 New Jersey Avenue, SE Washington, DC 20590 OCT 1 5 2019 Oberst Mulet CT Engineer II The Hartford Steam Boiler Inspection and Insurance Co. 1 State Street P.O. Box 5024 Hartford, CT 06102-5024 Reference No. 19-0051 Dear Mr. Mulet: -This letter is in response to your April 16, 2019, email requesting clarification of the Hazardous Materials Regulations (HMR; 49 CFR Parts 171-180) applicable to DOT 3AL seamless aluminum cylinders. Specifically, you ask whether the words "significant change" as used in § 178.46(c)(6) means an increase or decrease of the given criteria or just an increase in water capacity or base thickness, or the number of openings. Section l 78.46(c)(6) defines "significant change" applicable to DOT 3AL seamless aluminum cylinders as a 10% or greater change in cylinder wall thickness, service pressure, or diameter; a 30% or greater change in water capacity or base thickness; any change in material; over 100% increase in size of openings; or any change in the number of openings. The word "change" in the above paragraph means either an increase or decrease, meaning a "30% or greater change in water capacity" could be a 30% increase or a 30% decrease. Any of the above conditions would result in the change being considered significant for the purposes of§ 178.46(c)(6). I hope this information is helpful. Please contact us if we can be of further assistance. Sincerely, T. Glenn Foster Chief, Regulatory Review and Reinvention Branch Standards and Rulemaking Division <<>> Dodd, Alice (PHMSA) - From: Sent: To: Subject: /9-al.5' INFOCNTR (PHMSA) Wednesday, April 17, 2019 5:04 PM Hazmat Interps FW: Significant change clause Hello Alice and lkeya, Below is a request for interpretation from Mulet Oberst. Thanks, Jonathon, HMIC From: Mulet Oberst - Hartford-HSB [mailto:Oberst_Mulet@hsb.com] Sent: Tuesday, April 16, 2019 4:51 PM To: INFOCNTR (PHMSA) Subject: Significant change clause To: The Office of Hazardous Materials Standards; I have the following inquiry regarding 178.46(c)(6) "significant change": Background: In paragraph 178.46(c) of the 49 CFR, the word change instead of the words increased or decreased is used in two places as shown below in bold italics when compared to Clause 4.14.1 of CSA 8339-18. 49 CFR - 178.46(c)(6) " ... a 30 percent or greater change in water capacity or base thickness" more. " ... or a change in the number of openings. B339-18, Clause 4.14.1 I) the water capacity is increased by 30% or f) the number of openings in the finished container is increased. Question: In 49 CFR, paragraph 178.46(c)(6), does the word "change" means either an increase or decrease of the given criteria in which exceeding such upper or lower criteria of the water capacity, or base thickness, or number of openings would constitute a significant change to an acceptable design requiring qualification by prototype testing? Best regards; Oberst Mulet CT-Engineer II The Hartford Stearn Boiler Inspection and Insurance Co. One State Street PO Box 5024 1 <<>> Jrtford , CT 06102-5024 , elephone +1 (860) 722-5528 Facsimile Oberst Mulet@hsb.com www.munichre.com/HSB .... I R_is_k_S_o_lu_t_io_n_s ___ 7 ~ ® - Munich RE ::s=- Hartford S11iam Bo ll1ir IMPORTANT NOTICE The information in this email (and any attachments hereto) is confidential. If you are not the intended recipient , you must not use or disseminate the information. If you have received this email in error, please immediately notify me by "Reply" command and permanently delete the original and any copies or printouts thereof. Although this email and any attachments are believed to be free of any virus or other defect that might affect any computer system into which it is received and opened, it is the responsibi lity of the recipient to ensure that it is virus free and no responsibility is accepted by The Hartford Steam Boiler Inspection and Insurance Company or its subsidiaries or affiliates either jointly or severally, for any loss or damage arising in any way from its use. 2 ## Provenance - Official: Yes - Source: - Source ID: `phmsa` - SHA-256: `d8d678065e6c7d6f8ea75c0a606191f49fac74e5ea83e070ea02778aa7d9997f` - Retrieved: 2026-08-20T00:59:31.977Z - Exported: 2026-08-22T21:56:09.004Z - Document slug: `phmsa-interpretation-19-0051` ### Source metadata ```json { "materialSubtype": "interpretation", "interpretationArea": "hazardous_materials", "representation": "full_text_from_official_pdf", "companies": [ "The Hartford Steam Boiler Inspection and Insurance Co." ], "individuals": [ "Oberst Mulet" ], "refIds": [ "19-0051" ], "catalogDates": [ "2019-10-15" ], "catalogParts": [ 178 ], "catalogRowCount": 1, "sourceRecordUrls": [ "https://www.phmsa.dot.gov/node/71786" ], "linkedAttachmentUrls": [], "unavailableResponseUrls": [], "duplicateRepresentationUrls": [], "citedSections": [ "178.46", "178.46(c)(6)" ], "catalogPageUrls": [ "https://www.phmsa.dot.gov/regulations/title49/section/17846" ], "pdfUrls": [ "https://www.phmsa.dot.gov/sites/phmsa.dot.gov/files/docs/standards-rulemaking/hazmat/interpretations/72711/190051.pdf" ], "representations": [ { "viewUrl": "https://www.phmsa.dot.gov/sites/phmsa.dot.gov/files/docs/standards-rulemaking/hazmat/interpretations/72711/190051.pdf", "detailUrl": null, "detailHtmlPath": null, "pdfUrl": "https://www.phmsa.dot.gov/sites/phmsa.dot.gov/files/docs/standards-rulemaking/hazmat/interpretations/72711/190051.pdf", "pdfArtifactPath": "data/sources/phmsa-interpretations/19-0051-4c87906ef3.pdf", "pdfArtifactSha256": "0bc4bc331983564aa9d157109a40c2a63fe940766a4eb245b12a4c7cbda16031", "extractedTextPath": "data/sources/phmsa-interpretations/19-0051-4c87906ef3.v2.txt", "extractedTextSha256": "7915a8a9e62451b2a849f666efaafe77df607513112454d2b7fe25a2ea05f1d8", "pageCount": 3, "extractionVersion": 2 } ], "caveat": "Interpretations apply regulations to the facts presented and do not create independently enforceable requirements.", "jurisdiction": "US" } ```