{"operation":"document","citation":"08-0025","title":"HMT Associates, L.L.C. — Hazardous Materials Safety Interpretation","source_type":"guidance","agency":"Pipeline and Hazardous Materials Safety Administration","status":"guidance","official":true,"published_on":"2008-02-25","effective_on":null,"summary":"08-0025 response to HMT Associates, L.L.C. concerning 173.124, 173.125.","machine_formats":{"json":"https://regulus.evalyn.ai/document/phmsa-interpretation-08-0025.json","markdown":"https://regulus.evalyn.ai/document/phmsa-interpretation-08-0025.md"},"app_url":"https://regulus.evalyn.ai/document/phmsa-interpretation-08-0025","source_url":"https://www.phmsa.dot.gov/sites/phmsa.dot.gov/files/legacy/interpretations/Interpretation%20Files/2008/080025.pdf","body":"<<<PAGE 1>>>\n\nU.S. Department\nof Transportation\nPipeline and Hazardous\nMaterials Safety\nAdministration\n1200 New Jersey Avenue. SE\nWashington, D.C. 20590\nMr. E.A. Altemos\nHMT Associates, L.L.C.\n603 King Street, Suite 300\nAlexandria, VA 22314-3105\nRef. No. 08-0025\nDear Mr. Altemos:\nThis is in response to your letter of October 2,3007 requesting guidance regarding the\nrequirements of the UN Manual of Tests and Criteria (UN Test Manual). Specifically,\nyou request clarification regarding the test method for readily combustible solids (test\nmethod N. 1). Your questions are paraphrased and answered as follows:\nQ l ) As referenced in 33.2.1.4.4, do the words \"over the entire length of the sample \"\nrefer to the 100 mm length over which the testprocedure in 33.2.1.4.3.2.3 requires the\nburning rate to be measured, or to the entire 250 mm length of sample deposited on the\ntest surface by the 250 mm long mould?\nAl) The words \"over the entire length of the sample\" refer to the 100 mm length over\nwhich the test procedure in 33.2.1.4.3.2.3 requires the burning rate to be measured. You\nwill note that 33.2.1.4.4 refers to the \"rate of burning\" and 33.2.1.4.3.2.3 states \"when the\npile has burned a distance of 80 rnm, measure the rate of burning over the next 100 mm.\"\nQ2) The test manual procedure and classijication criteria vary in certain respects\ndepending on whether the material tested is a metal powder or whether it is a substance\n\"other than a metal powder\". Your guidance concerning the intent of the UN Test N.1\nregarding the testing and classrj?cation of mixtures of metal powder and substances\n\"other than metal powders \" is requested.\nA2) It is our opinion that a powder which is a mixture of metal powder and \"other than\nmetal\" powder should be tested in accordance with the method described for metal\npowders. We do not believe the method as currently worded allows for a quantification\nof the risk based on the powder's composition.\nIn your letter you also ask whether it may be necessary to seek clarification of the test\nmethod fiom the UN Sub-Committee of Experts on the Transport of Dangerous Goods.\nIn our opinion, the text is clear with respect to the burning rate issue identified in your\nfirst question. However, we would not be opposed to considering an amendment\n\n<<<PAGE 2>>>\n\nclarifying the applicability of the test method to a powder which is a mixture of metal and\n\"other than metal\" powders if a majority of the Sub-committee members are in\nagreement that such a clarification is necessary.\nI hope this information is helpfbl. Please feel free to contact me if I can be of further\nassistance.\nSincerely,\n&uT~# Edward T. Mazzullo\nDirector, Office of Hazardous Materials Standards\n\n<<<PAGE 3>>>\n\nHMT ASSOCIATES, L.L.C. 603 KING ST.\nSUITE 300\nALWNDRIA, VA 2231 4-31 05 703-5490727\nFACSIMILE: 703-5490728\n9173.1z\"Ii)@)\ntj 173. 1 ~5 , ~ b )\nT e s t / 0\nE.A. ALTEMOS\nPATRICIA A. QUlNN\nWRITER'S DIRECT DIAL NUMBER\n(703) 549-0727, Ext. 11\nOctober 2,2007\nMr. Robert A. Richard\nDeputy Associate Administrator\nFor Materials Safety (PHH-2)\nPipeline and Hazardous Materials\nSafety Administration\nDepartment of Transportation\n1200 New Jersey Avenue, SE\nEast Building, 2\"d Floor\nWashington, D.C. 20590-0001\nDear Mr. Richard:\nThis is to request your guidance regarding the interpretation of Test N. 1 (\"Test method for\nreadily combustible solids\") appearing in 33.2.1.4 of the United Nations (UN) Manual of Tests and\nCriteria (\"the UN Test Manual\"), as that test relates to the classification of, and assignment of\npacking groups to metal powders. This test is incorporated by reference at tj tj 173.124(a)(3) and\n173.125(b) of the Hazardous Materials Regulations (HMR).\nThere are two specific aspects of the test for which your guidance is sought. The first relates\nto the length of the sample of metal powder over which the rate of burning is to be timed in the\n\"Burning rate test\" in 33.2.1.4.3.2. As prescribed in 33.2.1.4.3.2.1, the 250 rnm long mould\n(described in 33.2.1.4.2) is to be used to place the sample of metal powder to be tested on the test\nsurface. The metal powder is then ignited, and as stated in 33.2.1.4.3.2.3, \"[wlhen the pile has\nburned a distance of 80 rnm, measure the rate of burning over the next 100 rnm.\" However, where\nin each of the three paragraphs in 33.2.1.4.4 (\"Test criteria and method for assessing results\") the\ncriteria for classification and packing group assignment for metal powders is presented, it refers to\nthe time taken for the reaction to spread \"over the whole length of the sample\". It is unclear in this\nregard whether the \"whole length of the sample\" is the 100 mrn length over which the test procedure\nin 33.2.1.4.3.2.3 requires the burning rate to be measured, or whether this means the entire 250 mm\nlength of sample deposited on the test surface by the 250 rnm long mould. My understanding of the\nintent of the test, based on my reading of the test as well as a brief telephone conversation with Dr.\nKe, is that for purposes of metal powders the reference to the \"whole length of the sample\" in each\n\n<<<PAGE 4>>>\n\nJ HMT ASSOCIATES, L.L.C.\nMr. Robert A. Richard :-\nOctober 2, 2007\nPage 2\nof the three paragraphs in 33.2.1.4.4 is intended to mean the 100 rnm length of sample over which\n33.2.1.4.3.2.3 requires the burning time to be measured. However, your confirmation of this\nunderstanding is requested.\nThe second aspect of the test regarding which your guidance is requested relates to the testing\nof materials that are mixtures of metal powders with other materials (i.e., materials not metal\npowders). The test procedure and classification criteria vary in certain respects depending on\nwhether the material tested is a metal powder or whether it is a substance \"other than a metal\npowder\". However, it is not clear fiom the test how materials that are mixtures of metal powders\nand \"other than metal powders\" are to be tested and classified. If such a mixture is substantially a\nmetal powder (e.g., 95 per cent or more metal powder), it seems reasonable that the procedure and\nclassification criteria relating to metal powders should be employed. However, for example for a\n70130 or a 50150 mixture of metal powder to \"other than metal powder\", the test procedure and\ncriteria to be used are far fiom clear. It would seem reasonable that if the \"other than metal powder\"\ncomponent in the mixture is, itself, not \"readily combustible\" according to the \"preliminary\nscreening test\" or \"burning rate test\" in 3 3.2.4.1, then the mixture of that material with metal powder\nshould be tested and classified as appropriate for a metal powder. However, if the \"other than metal\npowder\" component of the mixture is, itself, a readily combustible material, it is unclear whether the\nmixture is to be tested and classified as a \"metal powder\" or as a substance \"other than a metal\npowder\". Your guidance concerning the intent of the UN Test N.l regarding the testing and\nclassification of mixtures of metal powder and substances \"other than metal powders\" is requested.\nFinally, I note that given the ambiguity of the text of the Test N. 1 as it currently appears in\nthe UN Test Manual, it may be necessary to seek clarification of the test method by the UN\nCommittee. Your views regarding the need for such action would also be appreciated.\nThank you for your consideration of this matter, and please do not hesitate to contact me if\nyou have questions concerning this request, or if you require additional information.\nSincerely,\nE. A. Altemos\ncc: Dr. Charles Ke (PHH-21)\nMr. Duane Pfund (PHH-5)\nMr. Shane Kelley (PHH-5)","truncated":false,"body_characters":7594}