URS Corporation — Hazardous Materials Safety Interpretation

Page 1U.S. Department of Transportation Pipeline and Hazardous Materials Safety Administration 1200 New Jersey Ave, S.E. Washington, D.C. 20590 MAR 0 9 2009 Ms. Erin N. Jarman Environmental Scientist URS Corporation 1600 Perimeter Park Drive Morrisville, NC 27560 Ref. No. 08-0308 Dear Ms. Jarman: This responds to your December 15,2008 letter and subsequent conversation with a member of my staff regarding the applicability of the Hazardous Materials Regulations (HMR; 49 CFR Parts 171-180) to the transportation of a non-compartmentalized cargo tank containing multiple materials. Specifically, you state that a cargo tank is loaded with both a corrosive liquid and a combustible liquid with a flash point ranging between 160 - 200" F; however, after loading, the two hazardous materials "separate" into two distinct layers inside the tank. You ask whether you should select a proper shipping name for each unique material contained in the tank or select a proper shipping name based solely on the hazard posed by the corrosive material. Under 5 173.22, it is the shipper's responsibility to properly class a hazardous material. This Office does not perform that function. For purposes of classification and assignment of a proper shipping name, the two materials in the cargo tank should be treated in the manner it is being transported; that is, as a single material. Thus, you should select a proper shipping name that most appropriately describes the material and the hazards it presents in transportation (see 5 172.101(c)(l2)(ii)). Based on the limited information provided in your letter and supplementary correspondence, it is the opinion of this Office that one of the corrosive liquid n.0.s. descriptions listed in the Hazardous Materials Table could suffice as the proper shipping name that most appropriately describes the material, depending on the characteristics of the final single material present in the cargo tank. Also, it should be noted that the technical name(s) of the hazardous material must be entered in parenthesis in accordance with 5 172.101(b)(4) for these entries. By#

Page 2definition, a combustible liquid is a material with a flashpoint between 60' C (140' F) and 93' C (200' F) that does not meet the definition of any other hazard class. As you indicated, your final material meets the definition for a corrosive liquid, and therefore it would not be appropriate to classify the final material as "Combustible liquid, n.o.s., NA1993." I trust this satisfies your inquiry. Please contact us if we can be of further assistance. Sincerely, Hattie L. Mitchell Chief, Regulatory Review and Reinvention Office of Hazardous Materials Standards#

Page 3December 15,2008 Mr. Edward T. Mazzullo Director, Ofice of Hazardous Materials Standards U.S. DOTIPHMSA (PHH- 10) 1200 New Jersey Avenue, SE East Building, 2nd Floor Washington, DC 20590 Dear Mr. Mazzullo: 1 am writing to you with regards to a clarification of the requirements for shipping non-compartmentalized cargo tanks containing more than one hazardous material. On December'9,2008, we received a verbal clarification on this issue fiom Ms. Susan Gorsky of your office. While we appreciated Ms. Gorsky's response and found it to be very reasonable, we would like to request a formal written confirmation of her recommendation(s) for our records. The scenario presented to her is as follows: A non-compartmentalized cargo tank is transporting a corrosive liquid as well as another liquid which has been reclassed as a combustible liquid. The two materials separate into two distinct layers inside the tank and do not mix. Therefore, it is our determination that the materials do not meet the definition of a "mixture" which is provided in 49 CFR 5171.8. When selecting a proper shipping name (PSN), should we select a PSN for each of the unique materials contained in the cargo tank or select a PSN based solely on the hazard posed by the corrosive material? Per our conversation with Ms. Gorsky, we were instructed that it would be acceptable to use either of the following methods when describing our material: 1) Select a PSN which is appropriate for the corrosive hazard only and disregard the combustible hazard, or 2) Select a PSN which is appropriate for the corrosive hazard and put "Combustible Liquid" in parentheses as if it were a subsidiary hazard. Please confirm that either of the above scenarios would be acceptable for shipping these cargo tanks. Thank you in advance for your assistance. I look forward to your response. Sincerely, Erin N. Jarman Environmental Scientist URS Corporation 1600 Perimeter Park Drive Suite 400 Morrisville, NC 27560 Tel: 919-461-1478 Fax: 919-461-1371 Erin-Jarman@urscorp.com#