URS Corporation — Hazardous Materials Safety Interpretation

Page 1U.S. Department of Transportation FEB 1 1 2004 400 Seventh St., S.W. Washington, D.C. 20590 Special Programs Research and Administration Mr. Andrew N. Romach Ref. No. 04-0161 Corporate Regulatory Manager URS Corporation 1600 Perimeter Park Drive Morrisville, NC 27560 Dear Mr. Romach: This responds to your letter requesting our assistance in determining the correct shipping description for a metal powder, in a flammable liquid under the Hazardous Materials Regulations which meets the definition of a flammable solid, when suspended (HMR; 49 CFR Parts. 171-180). You posed a scenario of a material, Aluminum powder coated, 4.1, UN1309, PG II, suspended in a flammable liquid (solvent) mixture that has a flash point of about 63°F (Class 3, PG II). It is your understanding that 10853, Be Than 15C there are no proper shipping names listed in the S 172.101 Hazardous Materials Table (HMT) for these mixtures except for Zirconium suspended in a liquid, UN1308. I apologize for the delay in responding and any inconvenience it may have caused. You are correct that no specific or generic description for your material currently exists in the HMT. In your scenario, provided the aluminum powder is compatible with the flammable liquid in your mixture and the overall mixture does not meet the should be described as. "Flammable liquids, n.o.s. (1-methoxy-2- definition of another hazard class, it is our opinion that it propyl acetate, Xylene), 3, UN1993, PG II. " We anticipate proposing generic descriptions in the HMT for scenarios such as yours in a future rulemaking. I trust this satisfies your inquiry. Please contact us if we can be of further assistance. Hate z nicho Hattie I. Mitchell Chief, Regulatory Review and Reinvention Office of Hazardous Materials Standards 172.101 040161#

Page 2URS Corporation URS Morrisville, NC 27560 1600 Perimeter Park Drive Fax: 919.461.1371 Tel: 919.461.1220 July 6, 2004 andy_romach@urscorp.com Stevens Mr. Ed Mazzullo, Director Office of Hazardous Material Standards Research and Special Programs Administration 5172.101. U.S. Department of Transportation 400 7th Street, SW (DHM-10) Proper Shipping Name FAX: (202) 366-3012 Washington, DC 20590-0001 04-8161 Dear Mr. Mazzullo: I am writing to you to request a written regulatory interpretation clarifying what would be the most appropriate proper shipping name to use when transporting a metal powder that meets the definition of a flammable solid, when it is suspended in a flammable liquid. In the Hazardous Material Table (49 CFR suspended in a liquid.' 173.101), I found a proper shipping name that addressed a specific metal powder, zirconium: Zirconium roper shipping name lists a primary hazard class of Class 3 but lists no subsidiary hazards. Three Dry zirconium is classified as a 4.2; wetted zirconium is classified as a 4.1.) Thi: account, it would appear that the flammable liquid would become the primary and only conveyed hazard packing groups are listed, dictated by the flashpoint of the flammable liquid. Taking this precedence into for a flammable solid suspended in a flammable liquid. Coated, 4.1, UN1309, PGII) suspended in a solvent mixture of xylene and 1-methoxy-2-propyl acetate, A specific scenario that I recently encountered is an aluminum flake (classified as Aluminum Powder with overall solution flashpoint of about 63°F (Class 3, PGII): Chemical Name CAS No. Weight% 1-Methoxy-2-propyl acetate 108-65-6 40-50% Aluminum Powder 7429-90-5 50-60% Xylene 1330-20-7 5-10% suspended in a flammable liquid, n.o.s.; or Metal powder, flammable, suspended in a flammable liquid, I was unable to find a generic proper shipping name to describe this scenario, such as: Flammable solid, n.o.s. What would be the appropriate proper shipping name for the above-described solution? If a generic proper shipping name is selected, what would be the appropriate technical names to list and in what order? Thank you for your consideration of this request. Sincerely, Alike Andrew N. Romach Corporate Regulatory Manager URS Corporation ' In the International Civil Aviation Organization's (ICAO) Technical Instructions for the Safe Transport of the ongoing move toward harmonization, it would seem the DOT should align its proper shipping name with ICAO. Dangerous Goods by Air, the comparable proper shipping name is: Zirconium suspended in a flammable liquid. In#