{"operation":"document","citation":"17-0120","title":"Mihama Corporation — Hazardous Materials Safety Interpretation","source_type":"guidance","agency":"Pipeline and Hazardous Materials Safety Administration","status":"guidance","official":true,"published_on":"2018-09-07","effective_on":null,"summary":"17-0120 concerning 171.7, 173.301, 173.304a.","machine_formats":{"json":"https://regulus.evalyn.ai/document/phmsa-interpretation-17-0120.json","markdown":"https://regulus.evalyn.ai/document/phmsa-interpretation-17-0120.md"},"app_url":"https://regulus.evalyn.ai/document/phmsa-interpretation-17-0120","source_url":"https://www.phmsa.dot.gov/sites/phmsa.dot.gov/files/docs/standards-rulemaking/hazmat/interpretations/68441/170120.pdf","body":"<<<PAGE 1>>>\n\nU.S. Department\nof Transportation\nPipeline and Hazardous\nMaterials Safety\nAdministration\n1200 New Jersey Avenue, SE\nWashington, DC 20590\nSEP O 7 2018\nAndrea Kornbluth\nMihama Corporation\n200 Pinehurst A venue\nNew York, NY 10033\nReference No. 17-0120\nDear Ms. Kornbluth:\nThis letter is in response to your October 31, 2017, email requesting clarification of the\nHazardous Materials Regulations (HMR; 49 CFR Parts 171-180) applicable to pressure relief\ndevice (PRD) requirements for U.S. Department of Transportation (DOT) 39 specification\ncylinders. Specifically, you indicate that you fill these cylinders with \"UN3252,\nDifluoremethane or Refrigerant gas R 32, 2.1.\"\nIn accordance with§ 173.301(f)(4), a PRD is required on a DOT 39 specification cylinder\nregardless of the cylinder size or the filled pressure. When used for a liquefied Division 2.1\nmaterial, a DOT 39 specification cylinder must be equipped with a metal PRD; fusible PRDs for\nliquefied gases are not authorized. Furthermore,§ 173.301(f)(l) specifies that the PRD must be\nselected in accordance with CGA S-1.1 and CGA Pamphlet s~ 7, as incorporated by reference in\n§ 171.7.\nWe have paraphrased and answered your questions as follows:\nQl. You ask if a DOT 39 specification cylinder can be filled with more than 75 in3 of\n\"UN3252, Difluoremethane or Refrigerant gas R 32, 2.1.\"\nAl. The answer is yes. Generally, R 32 refrigerant gases are classified as liquefied Division\n2.1 flammable gases. Sections 173.304 and 173.304a provide the filling requirements for\nliquefied compressed gases and additional requirement for shipments of liquefied\ncompressed gases in specification cylinders and do not specify that a DOT 39\nspecification cylinder cannot be filled with more than 75 in3 of \"UN3252,\nDifluoremethane or Refrigerant gas R 32, 2.1.\"\nAs mentioned in your request, PHMSA published a revised safety advisory notice on\nApril 24, 2017, titled \"Hazardous Materials: Use of DOT Specification 39 Cylinders for\nLiquefied Flammable Compressed Gas\" [82 FR 18967; Notice No. 2016-14], which\nclarified that DOT 39 specification cylinders exceeding 75 in3 should not contain\nliquefied compressed cyclopropane, ethane, or ethylene, or liquefied petroleum gases.\nYour understanding is correct that this safety advisory did not apply to \"UN3252,\nDifluoremethane or Refrigerant gas R 32, 2.1.\"\n\n<<<PAGE 2>>>\n\nQ2. A2. Q3 . A3. Q4. A4. Please note that on July 26, 2016, PHMSA published a notice of proposed rulemaking\n(NPRM) titled, \"Hazardous Materials: Miscellaneous Amendments Pertaining to\nDOT-Specification Cylinders (RRR)\" [81 FR 48977; HM-234], which proposed to revise\nthe requirements for§ 173.304a and restrict the internal volume of a DOT 39 cylinder to\n1.23 liters (nominal 75 in3) for a liquefied flammable gas. This proposed amendment was\nbased on a petition for rulemaking (P-1622; PHMSA-2013-0201).\nYou ask if a DOT 39 specification cylinder filled with \"UN3252, Difluoremethane or\nRefrigerant gas R 32, 2.1\" can be fitted with a CG-1 PRD.\nThe answer is yes. As outlined in Table 3 of CGA S-1.1 , Methylene Fluoride (R 32) is\nauthorized to have a CG-1 PRD.\nYou ask if a DOT 39 specification cylinder filled with \"UN3252, Difluoremethane or\nRefrigerant gas R 32, 2.1\" can be fitted with a CG-7 PRD.\nThe answer is yes. As outlined in Table 3 of CGA S-1.1 , Methylene Fluoride (R 32) is\nauthorized to have a CG-7 PRD.\nYou ask if a previous letter of interpretation on this topic (Reference No. 11-0117)\napplies to the scenario in your request.\nThe answer is no. Reference No. 11-0117, issued by this Office on June 13, 2011,\naddresses PRD selection for a DOT 39 specification cylinder filled with HFO-1234yf\nshipped as \"UN3161, Liquefied gas, flammable, n.o.s. (2,3,3,3-Tetrafluroprop-1-ene),\n2.1.\" Reference No. 11-0117 does not reflect your scenario because you have a different\ncommodity. Further, as opposed to Methylene Fluoride (R 32), which is listed in Table 3\nof the CGA S-1.1, HFO-1234yf or 2,3,3,3-Tetrafluroprop-1-ene is not listed in Table 3,\nmeaning that further analysis must be conducted to select the appropriate PRD for the\ncylinder. Please note that HM-234 proposed to require the use of a CGA CG-7 PRD for\nliquefied flammable gases in DOT 39 specification cylinders when the gas is not listed in\nCGA S-1.1.\nI hope this information is helpful. Please contact us if we can be of further assistance.\nn\nChief, Standards Development\nStandards and Rulemaking Division\n\n<<<PAGE 3>>>\n\n~nuary, lkeya CTR (PHMSA)\nFrom:\nSent:\nTo:\nSubject:\nFoster, Glenn (PHMSA)\nWednesday, November 01, 2017 8:29 AM\nDodd, Alice (PHMSA); January, Ikeya CTR (PHMSA)\nQuestion regarding PRDs for DOT-39 cylinders\nCctcllev\nQ~l,nderS\nl13.30'+o....,..11~ .loo\n\\1-0l'2-0\nAlice/ lkeya,\nPlease have the inquiry below checked in as an lnterp and assigned to a Specialist.\nThanks,\nGlenn\nFrom: Foster, Glenn (PHMSA)\nSent: Wednesday, November 01, 2017 8:28 AM\nTo: 'Andrea Kornbluth' <akornbluth@mihama.com>\nSubject: Question regarding PRDs for DOT-39 cylinders\nMs. Kornbluth,\nThank you for your inquiry. I will forward it to the appropriate individuals have it checked in as a request for a Letter of\nInterpretation.\nRegards,\nGlenn\nFrom: Andrea Kornbluth [mailto:akornbluth@mihama.com]\nSent: Tuesday, October 31, 2017 12:32 PM\nTo: Foster, Glenn (PHMSA) <Glenn.Foster@dot.gov>\nSubject: Question regarding PRDs for DOT-39 cylinders\nDear Mr. Foster,\nOur company, a supplier of U.S.-made DOT-39 NRCs in Japan, understands from your revised safety advisory\nnotice of April 21, 2017 (Docket No. PHMSA-2016-0078; Notice No. 2016-14) that the 75 in3 volume limit\napplies to liquified compressed cyclopropane, ethane, ethylene, or liquified petroleum gases, and not to mildly\nflammable gases such as HFO-1234yfor R-32.\nWe would appreciate it if you could clarify the PRD requirements for gases in this mildly flammable\ncategory. In your letter to Mr. Steve Gentry of Worthington Cylinders dated June 13, 2011 (Reference No. 11-\n0117), you state in A2 that \"CGA Publication S-1.1 does, however, mandate a CG-7 PRD for other similar\nliquified compressed gases and it is the opinion of this Office that cylinders containing HFO-1234yf must be\nfitted with a CG-7 PRD.\" However, CGA Publication S-1.1 curreritly allows for cylinders filled with R-32 to\nbe fitted with a CG-7 or a CG-1. Is it acceptable for a DOT-39 cylinder filled with more than 75 in3 of R-32 to\nbe fitted with a CG-1 PD?\nThank you for your attention to this matter.\nSincerely,\n1","truncated":false,"body_characters":6489}