{"operation":"document","citation":"08-0178","title":"ExxonMobil Chemical Company — Hazardous Materials Safety Interpretation","source_type":"guidance","agency":"Pipeline and Hazardous Materials Safety Administration","status":"guidance","official":true,"published_on":"2008-10-03","effective_on":null,"summary":"08-0178 response to ExxonMobil Chemical Company concerning 172.101, 172.704.","machine_formats":{"json":"https://regulus.evalyn.ai/document/phmsa-interpretation-08-0178.json","markdown":"https://regulus.evalyn.ai/document/phmsa-interpretation-08-0178.md"},"app_url":"https://regulus.evalyn.ai/document/phmsa-interpretation-08-0178","source_url":"https://www.phmsa.dot.gov/sites/phmsa.dot.gov/files/legacy/interpretations/Interpretation%20Files/2008/080178.pdf","body":"<<<PAGE 1>>>\n\nU.S. Department\nof Transportation\nPipeline and Hazardous Materials\nSafety Administration\n1200 New Jersey Ave., SE\nWashington. DC 20590\nMr. Ronald J. Stokes\nExxonMobil Chemical Company\nIntermediates, Synthetics Product Stewardship\nP.O. Box 3 140\nEdison, New Jersey 088 18\nRef. No. 08-0 1 78\nDear Mr. Stokes:\nThis responds to your June 25,2008 letter requesting clarification of the classification and\ntraining requirements in the Hazardous Materials Regulations (HMR; 49 CFR Parts 17 1 - 180)\nfor rail shipments. Specifically, you ask whether the HMR apply to the transportation of\nmaterials that release hydrogen into the vapor space of a tank car.\nAccording to your letter, you ship various products by rail tank car. Some of these products\nmeet the HMR definition for combustible liquid; others do not meet the definition for any\nhazard class. In all cases, however, these products release unincorporated hydrogen into the\nvapor space of the tank car. The vapor pressure is less than 40 psi; however, the hydrogen\nhas been measured at between 2% and 80% concentration. The published flammable limits\n(LEL-UEL) of hydrogen are 4% and 75%. You ask how these materials should be classed\nand transported.\nUnder the HMR, hydrogen is classed as a flammable gas irrespective of the pressure it exerts\nin its packaging. A material that releases a hazardous amount of hydrogen into the vapor\nspace of its packaging during transportation must be classed and transported to address the\nhazard posed by the hydrogen unless the material is stabilized or inhibited to preclude such a\nrelease. For example, the release of hydrogen during transportation could be inhibited\nthrough the use of a nitrogen blanket, provided the vapor pressure of the nitrogen does not\nexceed 40 psi. If the materials you ship are stabilized or inhibited to preclude the release of\nhydrogen, they may be transported as unregulated materials or as combustible liquids, as\nappropriate.\nAlternatively, a material that does not meet the definition of any of the hazard classes defined\nin Part 173 of the HMR, but that releases hydrogen into the vapor space of its container or\npackaging under the conditions described in your letter may be described as \"UN 1049,\nHydrogen, compressed, 2.1\" and transported in accordance with all applicable requirements,\nincluding appropriate packaging and hazard communication. A material that meets the\ndefinition for a combustible liquid and releases hydrogen into the vapor space of its container\n\n<<<PAGE 2>>>\n\nor packaging under the conditions described in your letter may be described as \"UN 1954,\nCompressed gas, flammable, n.o.s., 2.1 ( hydrogen, compressed; combustible liquid)\" and\ntransported in accordance with all applicable requirements, including appropriate packaging\nand hazard communication.\nYou also ask whether a person who loads or unloads non-hazardous materials to or from a\nbulk packaging must be trained in accordance with Subpart H of Part 172. The answer is no.\nThe training requirements in the HMR do not apply to persons who handle unregulated\nmaterials. However, persons who load andlor unload hazardous materials as described in this\nletter must be trained.\nI hope this answers your inquiry.\nSincerely,\nSusan Gorsky\nActing Chief, Standards Development\nOffice of Hazardous Materials Standards\n\n<<<PAGE 3>>>\n\nExxonMobil Chemical Company\nIntermediates, Synthetics Product Stewardship\nP.O. Box 3140\nEdison, New Jersey 08818\n732 321 6033 Telephone\n732 321 6057 Facsimile\nQj72. lo!\nbtl/,cab& a\nExonMobil lm~fllflg\nChemical bgfl/78\nJune 25.2008\nU.S. Department of Transportation\nPipeline and Hazardous Materials Safety Admin (PHH- 10)\nOffice of Hazardous Materials Safety\n1200 New Jersey Avenue, SE East Building, 2nd Floor\nWashington, DC 20590\nAttn: Mr. Edward T. Mazzullo, Director\nOffice of Hazardous Materials Standards\nDear Mr. Mazzullo:\nTwo matters recently arose for which we seek your consideration. The first matter deals with a few select\nproducts we produce and ship primarily by rail tankcar. These products vary from being a combustible liquid;\nn.0.s. to non-regulated but in all cases these products release unincorporated hydrogen into the vapor space of\nthe tankcar. While the vapor pressure is less than 40 psi, the hydrogen has been measured from 2% to 80%\nconcentration in air. The published flammable limits (LEL - UEL) of hydrogen are 4% to 75%. As you can see,\nwe don't havi'a Division 2.1 issue but we are concerned about the potential flammable and/or explosive issue\nsurrounding shipment of these products.\n1. Question. Based on the information stated above are there any hazardous material regulatory issues\n(classification & packaging) we should be concerned with.\n2. Question.'Are we correctly classifying our products by limiting the classifications where appropriate to\ncombustible liquid, n.0.s or non-regulated?\nThe second isiue deals with thiihiljkeit of no;-regulated and portable tanks.\nmaterkls in sdecification rail tank cars, cargo tanks\n3. Question. Are persons who only load and/or unload non-regulated materials to and fiom bulk specification\npackagings required to be trained in accordance with Subpart H to Part 172?\nAlthough we have the utmost appreciation for your time and obligations, we seek a prompt response so that we\nmay ensure only compliant shipments are placed into commerce.\nc':,! !,,.'.:.,'<.;, ,\n. ,\n:. . , , . ,'>. ' . .\n. . . . . . . . .\nSh6uldtheie ti6iaij~~uesti'on's: cbn$ernirig this r'iqhkst, I may be &itacted at the above address or contact\nnumbers shown below.\n. .\n, :i ; . :\n( I\n> .\nTharks for your help in this matter.\n. , ,\n. . . , , . . . . .\nSincerely, ' . ~ . . .\n. . , .\ni\n( ' . .\n' .:,.:',?\n. . ,\nTe1(732)321-6046' ' .,\" ' ' ' :. ..\n. .\n. .\n. .\n. .\nFax (732) 321-6057 . * . ..\n. . : . /,\nEmail: ron.j.stokzs@exxonmobil .com\n, .\nA Division of Exxon Mobil Corporation","truncated":false,"body_characters":5874}