{"operation":"document","citation":"09-0273","title":"Dow Corning Corporation — Hazardous Materials Safety Interpretation","source_type":"guidance","agency":"Pipeline and Hazardous Materials Safety Administration","status":"guidance","official":true,"published_on":"2010-03-01","effective_on":null,"summary":"09-0273 response to Dow Corning Corporation concerning 172.101, 173.124, 173.22.","machine_formats":{"json":"https://regulus.evalyn.ai/document/phmsa-interpretation-09-0273.json","markdown":"https://regulus.evalyn.ai/document/phmsa-interpretation-09-0273.md"},"app_url":"https://regulus.evalyn.ai/document/phmsa-interpretation-09-0273","source_url":"https://www.phmsa.dot.gov/sites/phmsa.dot.gov/files/legacy/interpretations/Interpretations/2009/090273.pdf","body":"<<<PAGE 1>>>\n\nU.S. Deportment of Transportation Pipeline and Hazardous Materials\nSafety Administration\n1200 New Jersey Avenue. SE\nWashington, OC 20590\nMAR 1 20lD\nMr. Stephen V. Moser\nAssistant General Counsel\nDow Corning Corporation\nMidland, Michigan 48686-0994\nRef. No.: 09-0273\nDear Mr. Moser:\nThis responds to your letter dated November 9,2009 regarding the proper hazard classification\nfor Chlorosilanes products under the Hazardous Materials Regulations (HMR; 49 CFR Parts\n171-180). Specifically, you ask whether Chlorosilanes products currently not classed as\nDivision 4.3 (Dangerous When Wet) materials in the § 172.101 Hazardous Materials Table\n(§ 172.101 HMT) meet the definition in § 173. 124(c) for a Division 4.3 (Dangerous When Wet)\nmaterial.\nAccording to your letter, you are seeking reaffirmation of your understanding of a previous\nletter, dated March 18, 1998, from the International Standards Coordinator for Hazardous\nMaterials Safety to Ms. Laura Neuwirth, Lathan & Watkins, that discusses subsidiary labeling\nrequirements for materials that meet Division 4.3 criteria.\nYou did not provide sufficient information (e.g., hazard characteristics, material safety data\nsheet (MSDS» for this Office to make a determination concerning the classification of your\nChlorosilanes products. Under § 173.22 ofthe HMR, it is the shipper's responsibility to\nproperly classify a hazardous material. This Office does not perform that function.\nAs you are aware, the § 172.10 I HMT specifically lists the basic description\n\"Trimethylchlorosilane, 3, UN 1298, II\", as a Class 3 (Flammable liquid) material with a\nsubsidiary hazard of Class 8 ( Corrosive). The proper labels for a Class 3 material having a\nsubsidiary hazard of Class 8 are the FLAMMABLE LIQUID and CORROSIVE hazard warning\nlabels. However, it is the shipper's responsibility to determine ifa material has any other\nsubsidiary hazards that require subsidiary hazard labels or placards under the provisions of\n§§ 172.402 and 172.505, respectively. Such determinations are not required to be verified by\nthis Office. If your material meets the definition for a Division 4.3 material as specified in\n§ 173. 124(c), then the shipping paper must note the Division 4.3 subsidiary hazard and the\n\n<<<PAGE 2>>>\n\npackage must bear a Division 4.3 label, whether or not the Division 4.3 subsidiary hazard is\nindicated in the §172.101 HMT entry for the material.\nI hope this information is helpful. If we can be of further assistance, please contact us.\nSincerely,\nlaL~~\n. ef, Standards Development\nOffice ofHazardous Materials Standards\n\n<<<PAGE 3>>>\n\neDOW GORNING\n[Y/j rulV1\nc§ 11 Z. lor\ng 113. fZY ~)\nNovember 9, 2009\n~ II Z. Ll 02 (cc.x..Z)\n~ (12\n. SO~)\n? l QC.u.rd I ':jU.S. Department of Transportation\nPHMSA Office of Hazardous Materials Standards \n 09- 0213\nAttn: PHH-10\nEast Building\n1200 New Jersey Avenue, S.E.\nWashington, DC 20590-0001\nRe: Request for Clarification\nDear SirlMadam:\nDow Coming Corporation (DCC) has determined that a number of its chlorosilanes\nmeet the definition of Dangerous When Wet (DWW) as set forth in 49 CFR Section\n173 .124( c), but are not already classified as D WW in the Hazardous Materials Table\n(49 CFR 172.101, the \"Table\"). For the reasons explained below, DCC respectfully\nrequests that PHMSA confirm that it is proper for DCC to label and placard these\nchlorosilanes as a subsidiary DWW hazard, based on the requirements of49 CFR\n172.402(a)(2) (relating to subsidiary hazard labels) and 49 CFR 172.505(c) (relating\nto placarding for subsidiary hazards).\nTo put this request in full context and assist PHMSA in its consideration ofthe issue\npresented, we offer the following additional information. Attached are two letters\nfrom 1998 between Frits Wybenga, U.S. DOT, and Latham & Watkins, then legal\ncounsel to the Silicones Environmental Health and Safety Council (SEHSC),\naddressing in part this subject. Also attached is a letter DCC has provided to carriers\nand officials since 1998 explaining why certain chlorosilanes are labeled and\nplacarded as they are.\nRecently, however, a tanker carrying trimethylchlorosilane was stopped by a New\nYork State trooper. The trooper and other state transportation officials with whom he\nconferred (NYSDOT) concluded that the shipment was improper because a DWW\nplacard was affixed to the tanker and the shipping papers referenced a subsidiary\nDWW hazard when there is no specific reference to Division 4.3 in Column 6 of the\nTable for trimethylchlorosilane. According to NYSDOT, DCC must use only\nshipping references and placards consistent with the specific hazard codes identified\nin the Table for the listed material and may not reference or placard for any other\nsubsidiary risk without special approval from U.S. DOT. When provided with copies\nof the 1998 letters noted above, NYSDOT stated that these letters were ambiguous\nand not satisfactory to establish the requisite U.S. DOT approval. NYSDOT\nrecommended that we seek clarification from PHMSA; hence, this request. Attached\nDow Corning Corporation\nMidland, Michigan 48686·0994\nPhone: (989) 496·4000\nwww.dowcorning.com\n\n<<<PAGE 4>>>\n\nU.S. Department of Transportation\nNovember 9, 2009\nPage 2\nfor your easy reference is a copy of the recent letter we sent to NYSDOT concerning\nthis matter.\nDow Coming is committed to safely transporting its products on America's highways\nand takes seriously its obligations to comply with the letter and spirit of all applicable\ntransportation safety regulations. We firmly believe it is our legal obligation (and the\nproper interpretation of the regulations and the Wybenga letter) to placard as DWW\nany and all products that meet the Division 4.3 criteria, whether that hazard is\nspecifically identified in the Table or not. Thus, we disagree with NYSDOT's\ninterpretation of the regulations as applied to our ongoing shipments of\ntrimethylchlorosilane and similarly situated chlorosilanes. However, we do agree that\nPHMSA is the best authority in this instance to address the propriety of our practices.\nThank you for your attention to this matter. If you have questions or require further\ninformation, please let me know. I can most easily be reached by telephone at (989)\n496-5843 or email atsteve.moser@dowcorning.com. We look forward to hearing\nfrom you at your earliest opportunity.\nVery truly yours,\n~tl.~\nStephen V. Moser\nAssistant General Counsel\nDow Coming Corporation\nAttachments\n\n<<<PAGE 5>>>\n\nLATHAM & WATKINS\nIODI DCANSILVANTA AVE NI\nATTORMETS AT LAW\nMET ALMORT OFFICE\nETIC ATO\nStat liage gure s4ñd\nMASIONGION, DC 20004•2305\nSult a00\nrESCENDer, 12014 2101811\nTAN 13051 00J 0101\nTELEPHOME 1202: 037•2200\nHERBOR UNISEC\nDai sutie ranies\nthat broca\nSAX 18021831 270%\nHİS YOHN HEW SORR 1002* a99)\naRE THIRD AVENUE QUITE IODID\nTELEPHONE 1212I 00G1100\nra6 1 44-171-2a 4400\n4448-514 aaaa\nLOS CHEELED CALORNIA CONTI POOR\nasa mess fifTH aracEt, durie daon\ncosta miza, CALiTOGNA 02020-1025\nTELEPHONE I TINI 5401258\nTELEGMUNE 1 P13= 105 183.\nTAR +78d 755-8200\n12812131 gur-aTax\nSAR ALRE ARIS\nBALAN CREICE\nJanuary 27, 1998\nPOL \"B' BISECT. SUItE 2-00\nTElEPHonE • 7.303 009.5455\n4x•7007ag9.sa8e\nscow, Ruse area\nTELEPHOnE 1000) 130-1830\n120 10191 004:7419\nPAI I HIE, 308.0001\nBY MESSENGER\nFrits Wybenga\nInternational Standards Coordinator\nRobert A. Richard\nAssistant International Standards Coordinator\nRSPA, DHM5, Room 8422\nU.S. Department of Transportation\n400 7th Street, S.W\nWashington, D.C. 20590-0001\nCharles H. Ke\nChief, Sciences Group\nOffice of Hazardous Materials Technology, Room 8430\nU.S. Department of Transportation\n400 7th Street, S.W.\nWashington, D.C. 20590-0001\nRe:\nSEHSC Proposal On The Regulation\nOf Materials That Emit Toxic Gas When Wet\nDear Messrs. Wybenga, Richard and Ke:\nOn behalf of the Silicones Environmental Health and Safety Council ('SEHSC\"), 1 want to\nexpress our appreciation for the time and attention you have given to SEHSC's proposal concerning the\nregulation of hazardous materials that emit toxic gas when wet, which we submitted to the U.S.\nDepartment of Transportation (\"DOT\") on March 21, 1997. In particular, we appreciate the opportunity\nwe had to meet with you on March 26, 1997, to discuss the recommendations in our proposal. This\nletter serves to confirm DOT's comments on SEHSC's proposal that were made during our March\n\n<<<PAGE 6>>>\n\nLATHAM & WATKINS\nFrits Wybenga\nRobert A Richard\nCharles H Ke\nJanuary 27, 1998\nPage 2\n26th meeting and to convey the commitment of SEHSC's members to implement handling and\nlabeling practices no later than the end of 1998 in accordance with this proposal on a\nvoluntary basis.\nA. Use of the \"Dangerous When Wet\" Label\nSEHSC's proposal recommends that the \"dangerous when wet\" (\"DWW\") label\nbe used as a subsidiary risk label for all chlorosilanes not currently classified as DWW by\nDOT, until such time as the Agency is able to revise its regulatory framework in a manner that\nboth requires and allows shippers of chlorosilanes to classify and label their materials. During\nour meeting, we reviewed the deficiencies in DOT's regulations that prevent shippers of\nchlorosilanes and other similar water reactive materials from determining whether the\nevolution of toxic gas from such materials when in contact with water is a primary or\nsecondary hazard. You indicated that SEHSC could use the DWW label as a subsidiary risk\nlabel for chlorosilanes not already classified as DWW if these chemical substances otherwise\nmeet the definition of DWW as set forth in 49 C.F.R. § 173.124(c).\nAs you are aware, the current DWW label has a flame on it which does not\nindicate the toxic hazard of some DWW materials. For chlorosilanes that are DWW because\nthey emit toxic gas when wet, DOT suggested that shippers also use either a poisonous by\ninhalation label or a marking explaining the nature of the DWW hazard. In particular, Fritz\nWybenga suggested that, in addition to a DWW subsidiary risk label, shippers of chlorosilanes\nmay want to place text on their containers that states \"emits toxic gas when wet.\" SEHSC\nmembers have decided to adopt Mr. Wybenga's suggestion for the labeling of domestic\nshipments of chlorosilanes, except for shipments of \"limited quantities\" - meaning quantities\nnot exceeding 2 liters.\nB. Clarification of the DWW Test Procedure\nIn addition to the labeling issue, SEHSC explained to DOT, both in its written\nproposal and at the March 26th meeting, that the DWW test procedure fails to specify how\nmuch water to use in determining whether a material is in fact DWW. See Appendix E to 49\nC.F.R. § 173.124(c). Based on our limited testing results, we noted that the amount of water\nused in testing a particular chlorosilane for evolution of flammable or toxic gas may determine\nwhether that substance should be classified as DWW. At our meeting, you indicated that it\nwould be appropriate to conduct such testing on a \"worst case\" basis. In other words, if a\nmaterial emits toxic or flammable gas in sufficient quantities to satisfy the DWW threshold\nwhen tested with any amount of water, then it should be classified as DWW.\n\n<<<PAGE 7>>>\n\nLATHAM &Watkins\nFrits Wybenga\nRobert A Richard\nCharles H. Ke\nJanuary 27, 1998\nPage 3\nYou also verbally approved the use of theoretical calculations, in addition to\nactual testing, to determine whether water reactive materials are in fact DWW. The flexibility to\nuse theoretical calculations avoids the need for repetitive testing of materials with various\namounts of water to determine the \"worst case\" release of flammable or toxic gas. This\nflexibility is especially helpful with chlorosilanes, the reactivity of which may vary significantly\ndepending on the quantity of water involved in testing such substances.\nC. Harmonization Between DOT Regulations and U.N .. Recommendations\nWe understand that, at this time, DOT does not plan to act on SEHSC's long\nterm proposal to (i) create a new Division 4.4 and label with a skull and crossbones for\nmaterials that emit toxic gas when wet, and (ii) revise the Precedence of Hazard Table to rank\nthe DWW-toxic'''' hazard in relation to other hazards listed in the Table. You have informed us\nthat DOT prefers to wait until the ongoing harmonization efforts with the United Nations (\"U.N.\")\nRecommendations on the Transport of Dangerous Goods are concluded. You also indicated,\nhowever, that the Agency would be supportive of a broader, industry-wide proposal to the U.N ..\non how to regulate materials that emit toxic gas when wet.\nSEHSC is most interested in working with its counterpart in Europe - the Centre\nEuropeen Des Silicones (\"CES\") - to present an industry-wide proposal to the U.N .. on\nDWW-toxic materials. Shortly after our meeting with DOT, we requested that the CES review\nand comment on SEHSC's long-term proposal. We also have set up a conference call meeting\nbetween the CES and SEHSC Operating Safety Committees to discuss all relevant DWW\nissues and to explore the possibility of an industry-wide position on the classification and\nlabeling of chlorosilanes. We will keep you apprised of significant developments on this matter.\n* * *\nOnce more, we express our appreCiation for your consideration of SEHSC's\nproposal. We would appreciate it if you could confirm in writing the accuracy of our\nunderstanding of DOT's position on the issues noted above -- in particular, (i) the use of the\nDWW label as a subsidiary risk label for all chlorosilanes not already classified as DWW\n(assuming they meet the DWW threshold); (ii) the use of theoretical calculations rather than\nactual testing to determine whether the DWW threshold is exceeded for a particular water\nreactive material; and (iii) implementation of the DWW testing procedure on a \"worst case\"\nbasis.\n\n<<<PAGE 8>>>\n\nLATHAM & WATKINS\nFrits Wybenga\nRobert A. Richard\nCharles H. Ke\nJanuary 27, 1998\nPage 4\nMy colleague, Greg Slater, has relocated from the Washington, D.C. area. Thus, if you have any\nquestions concerning this letter or SEHSC's proposal to DOT, please do not hesitate to contact me at (202)\n637-2239, or SEHSC's Executive Director, William Smock, or Deputy Director, Beth Dombrowsky, at (703)\n438-3943.\nVery truly yours,\nJulia A. Hatcher\nof LATHAM &WATKINS\ncc: William H. Smock SEHSC, Executive Director\nElizabeth C. Dombrowsky, SEHSC Deputy Director\nSEHSC DWW Work Group Members\nDC DOCS\\56247.1\n\n<<<PAGE 9>>>\n\nDow Coming INTERNAL\n\" \nUS Department of Transportation Washington, D.C. 20590\n400 Seventh Street S. W,\nResearch and\nSpecial Programs\nAdministration\nLaura Neuwirth\nLatham & Watkins\nAttorneys at Law\n1001 Pennsylvania Avenue, NW\nWashington, DC 20004-2505\nDear Ms. Neuwirth:\nThis is in response to your letter of January 27, 1998 recording your\nunderstanding of the meeting held between representatives of Silicones\nEnvironmental Health & and Safety Council and representatives from our office\non March 26, 1997 We concur with your summary of points discusses at the\nmeeting. However, in relation to subsidiary risk labeling it should benoted that\n172.402(a)(2) requires the use of the 4.3 subsidiary risk label for substances\nmeeting the Division 4.3 criteria.\nSincerely,\nFrits Wybenga\nInternational Standards Coordinator\nfor Hazardous Materials Safety\nTitle:dotletter DWW Page 1 of 2\n\n<<<PAGE 10>>>\n\nDow Coming INTERNAL\nTitle:dotletter DIJIMI Page 2 of2\n\n<<<PAGE 11>>>\n\nDow Coming INTERNAL\nMay 26,1998\nTo: Interested Parties\nFrom: Dow Corning Corporation Transportation Regulatory Team\nSubject: Addition of Dangerous When Wet (DWW) Subsidiary Hazard to\nC h lorosilanes\nThe purpose of this letter and the attached letter from the DOT is to explain why\nmany chlorosilanes being shipped domestically by road and rail by Dow Corning\nCorporation have been re-classified as a subsidiary Dangerous When Wet.\nHopefully, this correspondence will address any confusion you may have\nregarding the domestic transportation of these materials.\nDow Corning Corporation recently reclassified many chlorosilanes that were not\nalready classed as DWW by the DOT, as a subsidiary DWW. This reclassification\nis ONLY for domestic transportation. This reclassification was based on recent\nlimited testing and knowledge of the nature of chlorosilanes that indicated that\nthese materials meet the definition of Dangerous When Wet in 49 CFR\n173.124(c). Dow Corning Corporation and the Silicones Environmental Health\nand Safety Council (SEHSC) met with the DOT regarding this issue. In summary,\nit was determined that the Dow Corning Corporation and other the SEHSC\nmember companies will start labeling and/or placarding chlorosilanes as a\nsubsidiary DWW hazard, if not already classed as a DWW by the DOT to meet\nthe requirements of 172.402(a)(2) and 172.505(c). In addition, it was agreed\nupon by the DOT that Dow Corning would also add an additional statement near\nthe label and/or placard that reads \"Emits Toxic Gas When Wet\". This explains\nwhy many chlorosilanes now are transported domestically as a subsidiary DWW\nand carry a statement that reads \"Emits Toxic Gas When Wet\".\nWayne Winslow\nSr. Transportation Safety and Regulatory Specialist\n/Attachment: DOT Letter Dated March 18, 1998\nletterDCC dw Page 1 of 1\n\n<<<PAGE 12>>>\n\nOctober 9,2009\nJustin Zimmerman\nMotor Carrier Investigator\nNew York State Dept ofTransportation\n11 Valley park Drive,\nAdams, NY 13605\nDear Mr. Zimmerman:\nThank you for taking the time this morning to talk wIth me and other representatives ofDow\nComing's Transportation Compliance team. I thought it was a helpful discussion, even ifwe\ncould not come to a full agreement on the application ofthe Hazardous Materials Transportation\nRegulations (49 CFR Parts 100-185, the \"HMR\") to certain shipments ofDow Coming products.\nThe purposes ofthis letter are: (I) to confirm Dow Coming's conunitment to follow up with the\nU.S. Department ofTransportation, Pipeline and Hazardous Materials Safety Administration\n(\"U.S. DOT\" or \"PHMSA\"); and (2) to document the gist ofour discussion this morning. We\nwant to avoid any confusion or misunderstanding regarding Dow Coming's knowledge of, and\ncommitment to full compliance with, the HMR. We also want to assure the safe and timely\nmovement ofour products in transit.\nAs we discussed, you recently stopped a tanker carrying trimethylchlorosilanethat had a\nDangerous When Wet (\"DWW\") placard on it. Dow Coming interprets the HMR to require\nsuch a placard. We base this on our knowledge of the hazards ofthe chemicals we produce and\ntransport and our reading ofthe requirements relating to identification ofsubsidiary hazards,\nfound in 49 CFR Sections 172.101(g), 172.402(a) and 172.505(c). We also base our\ninterpretation on the March 19, 1998 letter from Frits Wybenga ofU.S. DOT, written in response\nto a submission from the Silicones Environmental Health and Safety Council on this subject (the\n\"Wybenga letter\").\nFrom our discussion we have a better understanding ofyout concerns regarding the use ofa\nDWW placard when a material, like trimethylchlorosilane, is listed in the Hazardous Materi.als\nTable (49 CFR 172.101, the \"Table\") but there is no specific reference to Class 43 in Column 6\nofthe Table for that material. In short, we understand that your interpretation ofthe HMR is\nthat Dow Coming must use only placards consistent with the specific hazard codes ideptified in\nthe Table for the listed material and may not placard for any other subsidiary risk without special\napproval from U.S. DOT. You explained that you did not find the Wybenga letter satisfactory to\nestablish such U.S. DOT approvaL\nDow Corning Corporation\nMidlantl. Michig;m 4l!6R6-/}<}94\nPhone: (989)496-4000","truncated":false,"body_characters":19558}