{"operation":"document","citation":"22-0088","title":"DOT Training Solutions — Hazardous Materials Safety Interpretation","source_type":"guidance","agency":"Pipeline and Hazardous Materials Safety Administration","status":"guidance","official":true,"published_on":"2023-03-28","effective_on":null,"summary":"22-0088 response to DOT Training Solutions concerning 180.407.","machine_formats":{"json":"https://regulus.evalyn.ai/document/phmsa-interpretation-22-0088.json","markdown":"https://regulus.evalyn.ai/document/phmsa-interpretation-22-0088.md"},"app_url":"https://regulus.evalyn.ai/document/phmsa-interpretation-22-0088","source_url":"https://www.phmsa.dot.gov/sites/phmsa.dot.gov/files/2026-05/220088.pdf","body":"<<<PAGE 1>>>\n\n1200 New Jersey Avenue, SE\nWashington, DC 20590\nU.S. Department\nof Transportation\nPipeline and Hazardous\nMaterials Safety\nAdministration\nMarch 28, 2023\nMr. Rex Railsback\nSafety Consultant\nDOT Training Solutions\nP.O. Box 253111\nOverland Park, KS 66225\nReference No. 22-0088\nDear Mr. Railsback:\nThis letter is in response to your July 29, 2022, email requesting clarification of the Hazardous\nMaterials Regulations (HMR; 49 CFR Parts 171-180) applicable to the testing of insulated\nDepartment of Transportation (DOT) specification MC 331 cargo tanks. Specifically, you ask\nwhether previous Letter of Interpretation (LOI) No. 04-0221—issued on October 1, 2004—is\nstill valid, and request information as to how insulated MC 330 and MC 331 cargo tanks could\nbe exempt from compliance with the periodic test and inspection requirements found in Note 4 to\n§ 180.407(c) or § 180.407(d)(1).\nLOI No. 04-0221 discusses inspection requirements for MC 330, MC 331, and MC 338 cargo\ntanks in carbon dioxide, refrigerated liquid service. After reviewing LOI 04-0221, it is the\nopinion of this Office that the letter is still accurate and considered current.\nIn addition, nothing in § 180.407 exempts MC 330 or 331 cargo tanks from the requirements of\n§ 180.407(c) Note 4 or § 180.407(d)(1). The compliance dates specified in § 180.407(c) require\ninsulated MC 330 and 331 cargo tanks to undergo an internal visual inspection once every five\nyears. Section 180.407(d) states that insulated cargo tanks that cannot be entirely externally\ninspected due to the insulation must be internally inspected in the areas where external inspection\nis precluded. Further, if the inside of the cargo tank is lined, coated, or designed to prevent\naccess for an internal inspection, then the cargo tank must be hydrostatically tested.\n\n<<<PAGE 2>>>\n\nIn summary, while internal inspections are required every five years, either an internal inspection\nor a hydrostatic test must be conducted annually if insulation precludes a full external inspection.\nI hope this information is helpful. Please contact us if we can be of further assistance.\nSincerely,\nT. Glenn Foster\nChief, Regulatory Review and Reinvention Branch\nStandards and Rulemaking Division\n\n<<<PAGE 3>>>\n\nWolcott\n22-0088\nFrom: INFOCNTR (PHMSA)\nTo: Dodd, Alice (PHMSA)\nSubject: FW: Ref. 180.407(c), note 4, 180.407(d) and insulated MC 331 Cargo Tanks\nDate: Friday, August 26, 2022 2:28:11 PM\nHi Alice,\nPlease see the below interpretation request.\nLet us know if you need anything.\nRegards,\nJosh\nFrom: Rex Railsback <rex@dottrainingsolutions.com>\nSent: Friday, July 29, 2022 3:32 PM\nTo: INFOCNTR (PHMSA) <INFOCNTR.INFOCNTR@dot.gov>\nSubject: Ref. 180.407(c), note 4, 180.407(d) and insulated MC 331 Cargo Tanks\nCAUTION: This email originated from outside of the Department of Transportation (DOT). Do\nnot click on links or open attachments unless you recognize the sender and know the content\nis safe.\nRef. 180.407(c), note 4, 180.407(d) and insulated MC 331 Cargo Tanks\nI respectfully request a written response, to the following questions.\nPer 180.407(c), an insulated MC 331 cargo tank must have an external visual inspection annually.\nAdditionally, an internal visual inspection would be required every five years, due to insulated MC\n331’s being excepted from the 1 year requirement and the five year requirement stating is applies to\n“all other cargo tanks, except MC 338”. The 1 year section of the chart for internal visual inspections,\nsends you to “Note 4”. Note 4 states “Insulated cargo tanks equipped with manholes or inspection\nopenings may perform either an internal visual inspection in conjunction with the external visual\ninspection or a hydrostatic or pneumatic pressure-test of the cargo tank”. Note 4, would leave one\nto believe that external areas of an insulated MC 331, that cannot be inspected during an external\nvisual inspection, would require those hidden areas, to be internally inspected or perform a pressure\ntest, to satisfy the annual external visual inspection requirements.\n180.407(d)(1) states “Where insulation precludes a complete external visual inspection as required\nby paragraphs (d)(2) through (d)(6) of this section, the cargo tank also must be given an internal\nvisual inspection in accordance with paragraph (e) of this section. If external visual inspection is\nprecluded because any part of the cargo tank wall is externally lined, coated, or designed to prevent\nan external visual inspection, those areas of the cargo tank must be internally inspected. If internal\n\n<<<PAGE 4>>>\n\nvisual inspection is precluded because the cargo tank is lined, coated, or designed so as to prevent\naccess for internal inspection, the tank must be hydrostatically or pneumatically tested in\naccordance with paragraph (g)(1)(iv) of this section. Those items able to be externally inspected\nmust be externally inspected and noted in the inspection report.\nPHMSA has issued several interpretations since December 2004, that more or less state, areas that\ncannot be inspected to the satisfaction of the Registered Inspector during the required external\nvisual inspection, then those areas that cannot be externally inspected, must be inspected internally\nor a pressure test must be completed.\nHowever, 04-0221, issued October 2004, for insulated MC 331 CTMV, in Carbon dioxide, refrigerated\nliquid service, states that the exception for the internal visual inspection for insulated MC 330, 331\nor 338 cargo tanks, was not removed so insulated MC 331 cargo tanks would only be subject to\n180.407(e) every five years. 04-0221 further implies, that the inspection report for the external\nvisual inspection, will only have to list those items that were capable of being inspected during the\nannually required external visual inspection, without internally inspecting the hidden items.\nInterpretation 04-0221 appears to be the only interpretation to state this and appears to be\ncontradictory to all subsequent interpretations, ref., registered inspectors not being able to fully\ncomplete an external visual inspection, per 180.407(d), due to hidden area/components.\nIs it still PHMSA’s position, that 04-0221 is still a “current” interpretation? If so, can you please spell\nout the regulatory text, that exempts insulated MC 330, 331 cargo tanks, in Carbon dioxide,\nrefrigerated liquid service and/or any insulated MC 330, 331 cargo tank and/or CTMV, from\ncomplying with 180.407(d)(1) and/or 180.407(c), Note 4.\nOnce again, I am respectfully requesting a written response to the above questions.\nMy contact information is below\nRespectfully,\nRex C. Railsback\nSafety Consultant\nMain Office: 866.296.7394\nCell: 913-568-3001\nrex@dottrainingsolutions.com\nP.O. Box 253111, Overland Park, KS, 66225\ndottrainingsolutions.com\n\n<<<PAGE 5>>>","truncated":false,"body_characters":6792}