# Air Liquide USA LLC — Hazardous Materials Safety Interpretation - **operation:** document - **citation:** 13-0003 - **title:** Air Liquide USA LLC — Hazardous Materials Safety Interpretation - **source type:** guidance - **agency:** Pipeline and Hazardous Materials Safety Administration - **status:** guidance - **official:** true - **published on:** 2013-03-08 - **effective on:** Not available - **summary:** 13-0003 response to Air Liquide USA LLC concerning 172.202, 172.402. - **machine formats:** - **json:** https://regulus.evalyn.ai/document/phmsa-interpretation-13-0003.json - **markdown:** https://regulus.evalyn.ai/document/phmsa-interpretation-13-0003.md - **app url:** https://regulus.evalyn.ai/document/phmsa-interpretation-13-0003 - **source url:** https://www.phmsa.dot.gov/sites/phmsa.dot.gov/files/docs/standards-rulemaking/hazmat/interpretations/74156/130003.pdf **body:** <<>> U.S. Department of Transportation Pipeline and Hazardous Materials Safety Administration 1200 New Jersey Avenue, SE Washington, DC 20590 MAR 0 8 2013 Mr. Jerry W. Freeman Director, Transportation Compliance Air Liquide USA LLC 2700 Post Oak Boulevard, Suite 1800 Houston, TX 77056 Reference No. 13-0003 Dear Mr. Freeman: This is in response to your December 3, 2012 letter requesting clarification on the proper classification and shipping description of"Trisilylamine" (CAS No. 13862-16-3) under the Hazardous Materials Regulations (HMR; 49 CPR Parts 171-180). You state this chemical is a liquid developed for use in the semiconductor industry. You also state the material was tested in conformance with the hazardous material classification criteria prescribed in the HMR and determined to meet the following four hazard classes in order of precedence: • Division 6.1 (poisonous), Packing Group (PG) I, Hazard Zone B; • Division 4.3 (dangerous when wet), PG I; • Class 8 (corrosive, dermal), PG I; • Class 3 (flammable liquid), PG II. You ask if the proper shipping description "UN 3491, Toxic by inhalation, liquid, water- reactive, flammable, n.o.s. (Trisilylamine), 6.1, (4.3, 3), PGI, Zone B" is the most appropriate selection for shipping this material throughout the United States and internationally. The answer is yes. However, for transport within the United States in accordance with the HMR, § 172.402(a)(2) requires all hazardous materials with a Class 8, PG I, subsidiary hazard to be labeled with a subsidiary CORROSIVE hazard warning label in all modes of transport. Therefore, the subsidiary hazard class must be entered in the proper shipping description as well (see § 172.202(a)(3)). I hope this satisfies your request. Sincerely, ---Y r#~~cd::---- T. Glenn Foster Chief, Regulatory Review and Reinvention Branch Standards and Rulemaking Division <<>> f.clmon so Y1 .§172 ,Jo 1 ~ f73.2a., December 3, 2012 Certified Return- Receipt U.S. Department of Transportation Standards & Rulemaking Division- East Building Pipeline Hazardous Materials Safety Administration Attn: Mr. Charles E. Betts (PHH-10) 1200 New Jersey Avenue, SE Washington DC 20590-0001 ~/tlS~,:ficahoj/1 13 -oog Dear Mr. Betts, I am writing your office to request a formal letter of guidance and interpretation on the classification of Trisilylamine (TSA) [N(SiH 3h, CAS # 13862-16-3] that is processed by Air Liquide. TSA is a chemical substance developed for applications in the semiconductor industry, and has recent.y undergone a series of analytical and scientific tests to determine certain characteristics. These tests were conducted by various independent and specialized certified testing agencies over the course ofthe last several months. The results of these tests have revealed that TSA exhibits the following characteristics as defined by the classification criteria outlined in 49 CFR Subpart D of Part 173: • Hazard Class Division 6.1: Toxic by Inhalation (Inhalation Hazard Zone B), PG I • :· Hazarct'C:Iass··ofvi$icifi 4.3: 'Water Reactive, PG 1 • 'Haz'ard Cic\s"s 8: Corrosive (Dermal), PG I • l-la.zard Class 3: Flammable Liquid, PG II Based on 49·CFR §173.2a, Precedence of Hazard Table, available and appropriate D.O.T. Basic Descriptions' found in 49 CFR §172.101 (Hazardous Materials Table), Air Liquide has selected 'UN3491, Toxic by inhalation liquid, water- reactive, flammable n.o.s. (Trisilylamine)' for identifying TSA for shipments offered throughout the United States and international community, Correspondence with the US DOT Hazardous Materials Information Center and other professional and technical leaders within our industry concur with our decision. However, this description excludes the corrosive characteristics of TS/\. 1\,;r Liqulde 2nd its partners are seeking regulatory guidance and interpretation from your office on the proper :::lassification of TSA based on the current regulations of Title 49 CFR (Revised as of October 1, 2012). Air Liquide is committed to the safe and compliant transportation of hazardous materials. Should you have any questions or require fu.rther information, please do not hesitate to contact me directly at 713.624.8213 or by email at jerry.freeman@airliquide.com Respectfully, ,_ , . · ·. · :0 flnr )'{~i!-"'"'"'-n ,. \. 'J:-:: -: \.; ·. ' .:· ::• ' ·.· •: "Jerri; w: Freeman ~ ::.·•.•.•):-~ · ~· :)~'-·" · Director,.Tran~portation·cornpna·nce• Air Liquide USA iLG AIR UQUIDE USA LLC • 2700 Post Oak Boulevard, Suite 1800, Houston,TX 77056 Air Liquide (usR-