{"operation":"document","citation":"99-0249","title":"FMC Corporation — Hazardous Materials Safety Interpretation","source_type":"guidance","agency":"Pipeline and Hazardous Materials Safety Administration","status":"guidance","official":true,"published_on":"2000-08-25","effective_on":null,"summary":"99-0249 response to FMC Corporation concerning 173.31.","machine_formats":{"json":"https://regulus.evalyn.ai/document/phmsa-interpretation-99-0249.json","markdown":"https://regulus.evalyn.ai/document/phmsa-interpretation-99-0249.md"},"app_url":"https://regulus.evalyn.ai/document/phmsa-interpretation-99-0249","source_url":"https://www.phmsa.dot.gov/sites/phmsa.dot.gov/files/legacy/interpretations/Interpretation%20Files/1999/990249.pdf","body":"<<<PAGE 1>>>\n\nTransportatic\nS. Departme\n400 Seventh St., S.W.\nWashington, D.C. 20590\nAUG 25 2000\nMr. Ralph J. Mikida\nRef. No. 99-0249\nHazardous Materials Coordinator\nFMC Corporation\n1735 Market Street\nPhiladelphia, PA 19103\nDear Mr. Mikida:\nI apologize for the delay in responding to your letter concerning the requirement in 49 CFR\n173.31(d)(1)(vi) to carefully inspect a frangible (rupture) disc in a pressure relief device prior to\neach hazardous material shipment. This requirement has its origins in regulations of the Interstate\nCommerce Commission issued in 1921. The wording of this requirement was most recently\nrevised in a final rule published on September 21, 1995, under RSPA's Docket Nos. HM-175A\nand 201 (60 Fed. Reg. 49098).\nAs the language of § 173.31(d)(1)(vi) states, the purpose of this type of inspection is to check \"for\ncorrosion or damage that may alter the intended operation of the device.\" For that reason, in\nresponse to a comment submitted in a separate rulemaking proceeding under Docket No. HM-216\n(61 Fed. Reg. 28666, 28671; June 5, 1996), we stated in the preamble that RSPA and FRA\nbelieve in order to fully inspect a rupture disc (both top and bottom), the disc must be removed\nfrom the safety vent device. It has been FRA's experience that a rupture disc may appear normal\non the top side, but be severely damaged or corroded on the bottom side.\nYou and others have raised concerns about the language of the present rule and its application to\npersons that forward a loaded tank car received from another location or return a tank car with\nresidue. We anticipate initiating a rulemaking in the near future to address these concerns.\nSincerely,\nI. All.\n| Edward T. Mazzull\noms,\nem\nDirector, Office of Hazardous\nMaterials Standards\n173,31\n990249\n-\n\n<<<PAGE 2>>>\n\nFMC Corporation\nMack\n1735 Market Street\n215 299 6000\nPhiladelphia Pennsylvania 19103\n8173.31\n99-8249\nFMC\nSeptember 2, 1999\nMr. Edward Mazzullo\nDirector, Office of Hazardous Materials Standards\nResearch and Special Programs Administration\nU.S. Department of Transportation\nDHM-10\n400 Seventh Street,\nSW\nWashington, D.C. 20590\nRe: Interpretation of 49 CFR, § 173.31 (d) (1) (vi)\nDear Mr. Mazzullo:\nTransportation\nWe are writing to outline concerns with a Department of\nreferenced\nabove.\n(DOT) interpretation of the regulations\nperforming an \"EXTERNAL visual inspection\" to determine that\nSection 173.31 (d) (1) has to do with\na tank car\ntransportation.\nThis includes, as stated in §\nsafe for\n173.31 (d) (1) (vi), \"The pressure relief device, including a\ncareful inspection of the frangible disc in non-closing\nalter the intended operation of the device\".\npressure relief devices, for corrosion or damage that may\nWe understand that the DOT is interpreting $ 173.31(d) (1) (vi)\ndisc each time\nto require removal and inspection of both sides of a rupture\nproduct or\nresidue. This position seems to come from the\na tank car is offered for transportation with\npreamble of HM-216, a final rule unrelated to and which made\nno changes to this section. In HM-175A and 201, which\nestablished the wording in this section, the preamble made no\nmention of the external inspection requiring removal of the\nrupture disc and inspecting both the top and bottom.\ndisassemble pressure relief valves.\ndiscuss the practical impossibility of having to remove and\nTherefore, DOT is offering a contradictory interpretation of\na section\nrevised\nconfuses the regulated community, but also significantly\nin a different docket.\nThis not only\nrevises the scope of a regulation without allowing for\ninterpretation in a new rule making.\npublic comment.\nAt a minimum, DOT should include the new\n\n<<<PAGE 3>>>\n\nsafety related consequences do\nIn addition, we feel the time, cost, and possible adverse\nremoving the rupture disc to inspect the bottom side prior\nnot justify the benefits of\nto each loaded and residue shipment.\nevidenced in the case of residue cars where they normally\nThis is especiall]\naccidental release is virtually non-existent.\n99% outage and the chance of a\n1 rupture disa non-\n- Many products\nhave no corrosive effect upon the disc\nspecific service and these discs only can fail by\nis selected by the shipper for their\ndisassembly/reassembly increases the likelihood of\noverpressure or mechanical damage.\nContinual\nwell as increase wear, and possible improper\ndamage to the disc and/or its assembly hardware, as\nreassembly due to human error.\n- Removing the rupture disc can increase the potential\nof contaminating the railcar.\nreact adversely to contamination may require\nSome materials that\nadditional cleaning prior to each reloading.\nHydrogen peroxide, which FMC ships in railcars, could\ngrades of this material where even small amounts of\nbe an example of this.\nWe also ship high purity\ncontamination can lead to off spec product.\nAdditional tank car cleaning could add to employee\nexposure time,\nenvironmental discharges, out-of-\nservice time for the railcar, and costs.\nWe recommend that the shipper be required to determine the\nappropriate frequency for inspecting the product side of the\nproduct, the type and material of construction of the disc,\ndisc, but not to exceed 5 years.\nThis would be based on the\nhistory.\nthe disc manufacturers recommendations, and the service\ninternal and service equipment inspection requirements for\nThis would be consistent with 49 CFR § 180.509\ncars in corrosive service.\nWe respectfully request that you review the actions and\nconsequences that can result from continual\ndisassembly/reassembly of a railcar rupture disc.\nSincerely,\nRalph 8 Dihila\nRalph J. Mikida\nHazardous Materials Coordinator","truncated":false,"body_characters":5622}