# Transport Canada, TDG — Hazardous Materials Safety Interpretation **Citation:** 15-0042 **Type / status:** guidance / guidance **Agency:** Pipeline and Hazardous Materials Safety Administration **Effective:** Not stated **Published:** 2015-06-25 15-0042 response to Transport Canada, TDG concerning 180.205, 180.209. ## Document text <<>> U.S. Department of Transportatior 1200 New Jersey Avenue SE Washington, DC 20590 Pipeline and Hazardous Administration Materials Safety JUN 2 5 2015 Ms. Nida Chaudhary Transport Canada, IDG Place de Ville, Tower C, 9" Floor 330 Sparks Street ... Ottawa, Ontario K1A ON5 Ref. No.: 15-0042 Dear Ms. Chaudhary: This is a response to your February 27, 2015 email requesting further clarification of the requalification of Department of Transportation (DOT) specification cylinders under § 180.209 of the Hazardous Materials Regulations (HMR; 49 CFR Parts 171-180) with respect to guidance provided in letter of interpretation (LOI) Ref. No. 14-0067 issued June 5,2014. In the 14-0067 LOI, you sought clarification on the requalification requirements applicable to DOT specification cylinders that have an outside diameter of 2 inches or less and are less than 2 feet in length. You cited Note 1 to Table 1 (Requalification of Cylinders) in § 180.209 which states that "any cylinder not exceeding 2 inches outside diameter and less than 2 feet in length is excepted from volumetric expansion test." You specifically asked whether DOT specification cylinders below that size are subject to requalification by proof pressure test or an internal visual inspection. In our response to that question, we answered that "cylinders not exceeding 2 inches in outside diameter and less than 2 feet in length are not subject to any other pressure testing requirements or an internal visual inspection. However, small cylinders of this type must be tested and inspected prior to further use if they meet any of the criteria in § 180.205(d)." In your February 27, 2015 email, you ask for additional clarification and regulatory insight. Your questions are answered as follows: Q1. Is a cylinder less than 2" OD and 2' length exempt from all periodic requalification requirements? Al. The answer is yes. Small specification cylinders not exceeding 2 inches in outside diameter and less than 2 feet in length are not subject to the periodic requalification in § 180.209(a). However, small cylinders of this type must be tested and inspected prior to further use if they meet any of the criteria in § 180.205(d). 1 <<>> Q2. Specifically, for a cylinder such as a DOT-3AL that is less than 2" OD and 2' length, is there a requirement for the cylinder to undergo an EXTERNAL visual examination, be marked by a facility with a RIN, and have a record kept of this requalification? A2. The answer to this group of questions is no. Please see A1. Q3. Is the exemption for these smaller cylinders with regards to periodic requalification an exemption like that for the DOT-3E and DOT-4L specifications? A3. The exemptions for periodic requalifications of the cylinders you listed are similar. Please see Al. I hope this information is helpful. If you have any more questions, please do not hesitate to contact this office. Sincerely, Henn Froster T. Glenn Foster Chief, Regulatory Review and Reinvention Branch Standards and Rulemaking Division <<>> Nickels $ 180.209 reclassification Lylinder Dodd, Alice (PHMSA) 15-0042 From: Sent: Monday, March 09, 2015 1:00 PM To: Hazmat Interps Subject: FW: Request for Letter of Interpretation - 49 CFR 180.209 Shante/Alice, Please submit this for a formal letter of interpretation. Ms. Chaudhary spoke with Neal and Jordan. Thanks, Mike From: Chaudhary, Nida [mailto:Nida.Chaudhary@tc.gc.ca] To: INFOCNTR (PHMSA) Sent: Friday, February 27, 2015 5:22 PM Subject: Request for Letter of Interpretation - 49 CFR 180.209 Good day, I formerly submitted a request for interpretation regarding 49 CFR 180.209. My original request appears below. As a response I was issued the interpretation with Ref No.:14-0067. Please take this as a follow up request for interpretation to obtain further clarification. I require a response to the second part of my initial question: Is a cylinder less than 2" OD and 2' length exempt from all requalification requirements? For clarification purposes, I add the following follow-up questions: Specifically, for a cylinder such as a DOT-3AL that is less than 2" OD and 2' length, is there a requirement for the cylinder to undergo an EXTERNAL visual examination, be marked by a facility with a RIN and have a record kept of this requalification? Oris the exemption for these smaller cylinders with regards to periodic requalification an exemption like that for the DOT-3E and DOT-4L specifications? I understand from the original interpretation that periodic requalification with pressure test and internal inspection is not required, however the response was not clear with regards to external visual inspection. Thank you in advance, Engineer / Ingénieure Nida Chaudhary Tel.: (613) 998-0517 nida.chaudhary@tc.gc.ca Fax / Télécopieur: (613) 993-5925 Transport Canada, TDG / Transports Canada, TMD 330 Sparks Street / 330, rue Sparks, Ottawa, Ontario K1A ON5 Place de Ville, Tower C, 9th floor / Tour C, 9 ième étage (ASDD) 1 <<>> From: Chaudhary, Nida Sent: Tuesday, April 01, 2014 4:11 PM To: 'infocntr@dot.gov' Subject: Request for Letter of Interpretation - 49 CFR 180.209 Good day, This email is for a request for letter of interpretation My question is regarding 49 CFR 180.209 Table 1 note 1 (see highlighted below) Question: The wording of this note states that a cylinder below these dimensions is excepted from volumetric expansion test. Does this mean that a cylinder less than 2" OD and 2' length must undergo requalification by either proof pressure or visual examination instead? Or does this mean that this cylinder is exempt from all requalification requirements? For example, for a small DOT-3AL cylinder that is less than 2" OD and 2' length. TABLE 1—REQUALIFICATION OF CYLINDERS 1 made Specification under which cylinder was Minimum test pressure (psia) 2 (years) Requalification period DOT 3 DOT 3A, AA 3000 psig service (see § 180.209(g)). 303 times service pressure, except noncorsive 5, 10, or 12 (see § 180.209(b), (f), (h), and i) DOT ЗАX, ЗААХ DOT 3AL 5/3 times service pressure 3B. 3BN. ... 2 times service pressure (see 5/3 times service pressure.. . 5 or 12 (see § 180.209()) $ 180.209(a)). 5 or 10 (see § 180.209(f)) ЗНТ 5/3 times service pressure Test not required. 3Т 5 or 10 (see § 180.209(h)) § 180.209(g)). 4AA480 .... .. 2 times service pressure (see 5/3 times service pressure.... .. 3 (see S8 180.209(k) and 180.213(c)) service (see § 180.209(g)). 4B, 4BA, 4BW, 4B-240ET ... 2 times service pressure, except noncorrosive 0)) 5, 10, or 12 (see § 180.209(e), (f), and 4D, 4DA, 4DS (see § 180.209(g)). DOT 4E 2 times service pressure, except noncorrosive Exempion or special permit cylinder... Se current exemption or special permit se cure exe pion or special permit .. Test not required. subchapter for restrictions on use). Foreign cylinder (see § 173.301(i) of this As marked on cylinder, but not less than marking. 5/3 of any service or working pressure 5 (see §S 180.209(I) and 180.213(d)(2)) + Any cylinder not exceeding 2 inches outside diameter and less than 2 feet in length is excepted from volumetric expansion 2 For cylinders not marked with a service pressure, see § 173.301a(b) of this subchapter. Please note that I have spoken to DOT personnel about this issue before, specifically Mark Toughiry, but I would like a written letter of interpretation to present to the CSA B339 committee. We are working on a similar section for the Canadian standard that is adopted in Canadian regulations. Thank you in advance, Engineer / Ingénieure Nida Chaudhary Tel.: (613) 998-0517 Fax / Télécopieur: (613) 993-5925 2 <<>> nida.chaudhary@tc.gc.ca Transport Canada, TDG / Transports Canada, TMD 330 Sparks Street / 330, rue Sparks, Ottawa, Ontario K1A 0N5 Place de Ville, Tower C, 9th floor / Tour C, 9 ième étage (ASDD) ## Provenance - Official: Yes - Source: - Source ID: `phmsa` - SHA-256: `0934186427f1b4d434164f0bf3e8163542108fb054b9c2efacf53b9dc4dbb7b0` - Retrieved: 2026-08-20T00:59:31.977Z - Exported: 2026-08-24T09:22:02.423Z - Document slug: `phmsa-interpretation-15-0042` ### Source metadata ```json { "materialSubtype": "interpretation", "interpretationArea": "hazardous_materials", "representation": "full_text_from_official_pdf", "companies": [ "Transport Canada, TDG" ], "individuals": [ "Ms. Nida Chaudhary" ], "refIds": [ "15-0042" ], "catalogDates": [ "2015-06-25" ], "catalogParts": [ 180 ], "catalogRowCount": 2, "sourceRecordUrls": [ "https://www.phmsa.dot.gov/node/64951" ], "linkedAttachmentUrls": [], "unavailableResponseUrls": [], "duplicateRepresentationUrls": [], "citedSections": [ "180.205", "180.205(d)", "180.209", "180.213(c)", "173.301(i)", "173.301a(b)" ], "catalogPageUrls": [ "https://www.phmsa.dot.gov/regulations/title49/section/180205", "https://www.phmsa.dot.gov/regulations/title49/section/180209" ], "pdfUrls": [ "https://www.phmsa.dot.gov/sites/phmsa.dot.gov/files/legacy/interpretations/Interpretation%20Files/2015/150042.pdf" ], "representations": [ { "viewUrl": "https://www.phmsa.dot.gov/sites/phmsa.dot.gov/files/legacy/interpretations/Interpretation%20Files/2015/150042.pdf", "detailUrl": null, "detailHtmlPath": null, "pdfUrl": "https://www.phmsa.dot.gov/sites/phmsa.dot.gov/files/legacy/interpretations/Interpretation%20Files/2015/150042.pdf", "pdfArtifactPath": "data/sources/phmsa-interpretations/15-0042-74186fe2ef.pdf", "pdfArtifactSha256": "22c87d6db09be2602186f1c86d64bbaaaeee570a629f3f69072f21260b79156a", "extractedTextPath": "data/sources/phmsa-interpretations/15-0042-74186fe2ef.v2.txt", "extractedTextSha256": "8ccd5a16d6016ff24a292deedec792b69cc59df7e59a6760bf815d57b3349bff", "pageCount": 5, "extractionVersion": 2 } ], "caveat": "Interpretations apply regulations to the facts presented and do not create independently enforceable requirements.", "jurisdiction": "US" } ```