# Mr. Ed Van Schoick — Hazardous Materials Safety Interpretation **Citation:** 11-0103 **Type / status:** guidance / guidance **Agency:** Pipeline and Hazardous Materials Safety Administration **Effective:** Not stated **Published:** 2011-06-30 11-0103 concerning 173.301, 173.40. ## Document text <<>> U.S. Department 1200 New Jersey Avenue SE of Transportbtion Washington. DC 20590 Pipeline anid Hazardous Materials Safety Administrafion I JUN 30 2011 Mr. Ed Van \Schoick 18213 Bitterp Ave. Lutz, FL 335,58 Ref. No.: 11 ..:0 1 03 Dear Mr. Van Schoick: This responds to your letter requesting clarification ofthe Hazardous Material Regulations (HMR; 49 CFR Parts 171-180) applicable to fluorine. Specifically, you ask whether the closure requirements in § 173.40(c) apply to cylinders containing fluorine. The answer is yes. As specified in § 173.301(c), cylinders containing toxic gases and toxic gas mixtures meeting the criteria of Division 2.3 Hazard Zone A or B must conform to the requirements of § 173.40. While the Hazardous Materials Table references § 173.302 for non .. bulk packaging requirements for fluorine, this does not except cylinders containing fluorine from the applicable requirements of § 173.40, including the closure requirements described in paragraph § 173.40( c). I hope this answers your inquiry. Ifyou need additional assistance, please contact the Standards and Rulemaking Division. Sincerely, ,~ +'U/Ben Supko \ Chief, Standards iDevelopment Branch StaQdards and Rulemaking Division <<>> 2nd DRAFT revised Office of Hazardous Materials Standards PHMSA Attn: PHH-I0 US Department of Transportation 1200 New Jersey Ave., SE Washington, DC 20590-0001 1 would like to request clarification ofthe valve requirements specified in 49CFR173 .40( c) closures as they mayor may not apply to fluorine, compressed, UN1045 in nonbulk packagings. The opening sentence in paragraph 173.40 states "When this section is referenced for a Hazard Zone A or B hazardous material elsewhere in this subchapter, the requirements in this section are applicable to cylinders used for that material". Paragraph 173.40 consists of five subparagraphs and may be referenced by a Hazard Zone A or B material in part, or in its entirety. Subparagraph 173.40(a) Authorized cylinders, subparagraph 173.40(b) Outage and pressure requirements subparagraph 173 .40( d) Additional handling protection atid subparagraph 173.40(e) Interconnection address those four topics as they relate to matbrials in Hazard Zone A or B. Subparagraph 173.40(c) Closures. addresses I plugs or vahies, but only for cylinders containing certain Hazard Zone A materials. i Examples ofiHazard Zone A gases that reference 173.40 in its entirety include arsine, cyanogen ch~oride, phosphine, hydrogen selenide, phosgene, all n.o.s. compressed gases in Hazard Zdpe A, all n.o.s. liquefied gases in Hazard Zone A, etc. Each of these gases references 173.192 in column 8B of the Hazardous Materials Table in 172.101. Paragraph 173.192 Packagingfor certain toxic gases in Hazard Zone A states" When paragraph 17~.1 01 of this subchapter specifies a toxic material must be packaged under this section, only the following cylinders are authorized". Subparagraph 173 .192(b) states "Packagings must conform to the requirements of 173.40". With respect to gases, a packaging indudes the cylinder and the closure (plug or valve). See paragraph 171.8 Packaging. In column 8B ofthe Hazardous Materials Table, hydrogen cyanide, anhydrous, references paJragraph 173.195 Hydrogen cyanide, anhydrous, stabilized where it states in subparagrap~ 173 .195 (c) "Packagings for hydrogen cyanide must conform to 173.40". This would iIjtclude the cylinder and the valve. Column 8B ~fthe Hazardous Materials Table references paragraph 173.198 for nickel carbonyl. Suljlparagraph 173 .198(b) states "Packagings for nickel carbonyl must conform to 173.40". Again, this would include the cylinder and the valve. ! , Examples off,azard Zone A materials that reference only portions of 173.40 include bromine pentrfluoride which references 173.228 in column 8B of the Hazardous <<>> Materials T~ble. Subparagraph 173.228(b) states "A material in Hazard Zone A must be transported iIn a seamless specification cylinder conforming to the requirements of 173040. HoJever, a welded cylinder ... " Clearly just the cylinder is being addressed and not the entir~ packaging. See paragraph 171.8 Cylinder. Column 8B in the Hazardous Materials Table references 173.337 for nitric oxide. I Subparagra~h 173.337(a) states "Nitric oxide must be packaged in cylinders conforming to the requir~ments of 173040 ... " Again, just the cylinder portion ofthe packaging is being addre~sed. Column 8B tn the Hazardous Materials Table references paragraph 173.302 for numerous gases including Hazard Zone A materials: diborane, fluorine and sulfur tetrafluoride. Of these three gases, both diborane and fluorine are subject to additional restrictions as noted in subparagraphs 173.302( d) and 173.302( e ) respectively, neither ofwhich reference 173040 for their packagings. Subparagraph 173.302a( d) Diborane and diborane mixtures addresses fill restrictions and the last sentence states "Cylinder valve assemblies must be protected in accordance with 173.301(h)". That sentence reveals that the DOT is aware that the valves on diborane cylinders do not conform to the specifications in 173AO(c) in that there are two valves on each cylinder and neither of them thread directly into the cylinder, which is a requirement of 173AO(c). Paragraph 173.301(h) Cylinder valve protection is referenced instead of the more rigorous protection required in 173 AO(d). This is not an oversight. It is intentional. The valves (closures) on diborane cylinders are not required to meet the specifications of paragraph 173 AO(c). A generic gas classed the same as diborane, e.g., Compressed gas, toxic, flammable, n.o.S. Inhalation Hazard Zone A, 2.3, UN1953 references 173.192 in column 8B. Clearly the packaging would be different from diborane and all of 173040 would apply. If diborane was intended to meet the closure requirements in 173 AO(c), 173.192 would be referenced in column 8B instead of 173.302. Subparagraph 173.302a(e) Fluorine specifies which cylinders may be used and limits the contents by pressure or mass, whichever is lower. There is no mention of any valve restrictions and no reference to 173040 with regard to the packaging. A generic gas classed the same as fluorine, e.g. Compressed gas, toxic, oxidizing, corrosive, n.o.s. Inhalation Hazard Zone A, 2.3, UN3306 references paragraph 173.192 in column 8B in the Hazardous Materials Table rather than 173.302. This difference demonstrates, as in the case with diborane, that fluorine is not intended to comply with the closure requirements of 173AO(c) either. Paragraph 173.302(a) states that "A cylinder filled with a non-liquefied compressed gas (except gas in solution) must be offered for transportation in accordance with the requirements of this section and paragraph 173.301". In paragraph 173.301(c) Toxic gases and mixtures it states "Cylinders containing toxic gases and toxic gas mixtures meeting the criteria of division 2.3 Hazard Zone A or B must conform to the requirements ofparagraph 173040 and CGA S-l.l and CGA S-7". This has lead to some confusion. However, a careful reading of 173.301 (c) reveals that it applies to the cylinder <<>> not the packaging. eGA S-I.1 and eGA S-7 specify the type, quantity and location of Pressure Relief Devices (PRDs) required on cylinders. PRDs are forbidden on Hazard Zone A gases. Therefore, these two references apply to the Hazard Zone B gases referenced in l73.301(c). Since it does not say "Packagings containing toxic gases and toxic gas mixtures ...." It is only addressing the cylinder requirements contained in 173.40 not the closure/valve. Materials that are required to use the closures specified in 173 .40( c) have paragraphs that specifically refer to 173.40 for their packagings, e.g. 173.195 for hydrogen cyanide, anhydrous; 173.198 for nickel carbonyl etc. or they reference paragraph 173.192. Otherwise, 173.40(c) does not apply. Thank you for your attention to this matter. Ed Van Schoick 18213 Bittern Ave Lutz, FL. 33558 813-269-9279 713-817-8033 cell ## Provenance - Official: Yes - Source: - Source ID: `phmsa` - SHA-256: `cf40ad06ea9cfecbe17fa6206c97653419bebeba4585f2ff9d65cdc1f5b1f7df` - Retrieved: 2026-08-20T00:59:31.977Z - Exported: 2026-08-23T07:47:46.947Z - Document slug: `phmsa-interpretation-11-0103` ### Source metadata ```json { "materialSubtype": "interpretation", "interpretationArea": "hazardous_materials", "representation": "full_text_from_official_pdf", "companies": [], "individuals": [ "Mr. Ed Van Schoick" ], "refIds": [ "11-0103" ], "catalogDates": [ "2011-06-30" ], "catalogParts": [ 173 ], "catalogRowCount": 2, "sourceRecordUrls": [ "https://www.phmsa.dot.gov/node/47876" ], "linkedAttachmentUrls": [], "unavailableResponseUrls": [], "duplicateRepresentationUrls": [], "citedSections": [ "173.301", "173.301(c)", "173.40", "173.40(c)", "173.302", "173.192", "172.101", "171.8", "173.195", "173.198", "173.228", "173.337", "173.302a" ], "catalogPageUrls": [ "https://www.phmsa.dot.gov/regulations/title49/section/173301", "https://www.phmsa.dot.gov/regulations/title49/section/17340" ], "pdfUrls": [ "https://www.phmsa.dot.gov/sites/phmsa.dot.gov/files/legacy/interpretations/Interpretations/2011/110103.pdf" ], "representations": [ { "viewUrl": "https://www.phmsa.dot.gov/sites/phmsa.dot.gov/files/legacy/interpretations/Interpretations/2011/110103.pdf", "detailUrl": null, "detailHtmlPath": null, "pdfUrl": "https://www.phmsa.dot.gov/sites/phmsa.dot.gov/files/legacy/interpretations/Interpretations/2011/110103.pdf", "pdfArtifactPath": "data/sources/phmsa-interpretations/11-0103-590455b6ea.pdf", "pdfArtifactSha256": "54d967c2fc94c90695e5c7a5fcb93898bb4d2e5ba83519daa9e3bee731723bcd", "extractedTextPath": "data/sources/phmsa-interpretations/11-0103-590455b6ea.v2.txt", "extractedTextSha256": "7aae4a7890a19997069919a67f41ef257836acf4bc2ca64d77ee3915ee8d306e", "pageCount": 4, "extractionVersion": 2 } ], "caveat": "Interpretations apply regulations to the facts presented and do not create independently enforceable requirements.", "jurisdiction": "US" } ```