Tom Dunaway & Associates, Inc — Hazardous Materials Safety Interpretation

Page 1400 Seventh St., S.W. NOV 16 2004 Washington, D.C. 20590 Special Programs Research and Administration Mr. Robert Brown, Jr. Ref. No.: 04-0236 P.O. Box 712 Tom Dunaway & Associates, Inc. Antioch. California 94509 Dear Mr. Brown: This responds to your letter regarding the proper segregation and separation of a Division 5.1 (oxidizer) and a Class 8 (corrosive) liquid under the Hazardous Materials Regulations (HMR; 49 CFR Parts 171-180). Specifically, your questions concerns the segregation and separation requirements for hazardous materials identified by the letter "O" in § 177.848(e)(3). You state that you have a client who wishes to transport a Class 8 (corrosive) material and a Division 5.1 (oxidizer) material in a multi-compartmented cargo tank. Your questions are paraphrased and answered as follows: Q1. Are these hazardous materials authorized to be transported in adjacent or non-adjacent tanks of the same cargo tank? Al. The arswer is no. Section 177.848(a)(2) applies to materials that meet one or more hazard class definitions and are in a compartment within a multi-compartmented cargo tank subject to the restrictions in § 173.33. Section 173.33(a)(2) prohibits the loading of explosion, fire, excessive increase in pressure or heat, or the release of toxic vapors. This materials on the same cargo tank motor vehicle that, if mixed, could result in an restric ion applies regardless of whether the incompatible materials on the cargo tank motor vehicle are separated by adjacent compartments/tanks or non-adjacent compartments/tanks. 02. If the answer to Ql is no, would that answer change if the shipper certifies that the mixture of the contents would not create a fire or a dangerous evolution of heat or gas? A2. The ariswer is yes. Section 173.33(a)(2) is not intended to prevent the shipment of materials that, if mixed, would produce a moderate exothermic reaction that would not start a fire, rupture the tank, or release acutely toxic vapors. 193:33 (a) 2) 177.848 (a)z) 040236#

Page 2Many factors affect how materials may react with each other. They include the chemical composition and properties of the materials involved, and how they react to air, water, contaminants, or temperature conditions during transportation. Because there are so many variables, under the HMR, the parties involved must evaluate the potential risk posed by different materials that are offered and accepted for transportation on the same multi-compartmented cargo tank motor vehicle. If your client has specific questions on making these determination, your client may contact Mr. Charles Hochman, Office of Hazardous Materials Technology, at (202) 366-4545 for assistance. I hope this satisfies your request. Sincerely, Hotte 2. Michels Hattie L. Mitchell, Chief Regulatory Review and Reinvention Office of Hazardous Materials Standards#

Page 3Betts 8177848(0)2) Tom Dunaway & Associates, Inc. §173.33 (a) (8) Segregatior36 June 29, 2004 Office of Hazardous Materials Standards Research and Special Programs Administration Attn: DHM-10 U.S. Department Of Transportation 400 7" Street SW Washington, DC 20590-001 Clarification 49 CFR 177.848(a)(2)/173.33(a)(2) My questions concern the Segregation Requirements for materials identified by Note "O" in 177.848(e)(3). I have both phone and e-nailed the RSPA Information center. The responses to my inquiry only deal with non-bulk packages. A client wishes to transport a Class 8 corrosive material and a Division 5.1 oxidizing material in a multi-compartmented cargo tank. Q-1 May these materials be transported in adjacent compartments/tanks of the same cargo tank motor vehicle? Q-2 If the answer to Q-1 is no, may they be transported in non-adjacent compartments/tanks? Q-3 Would the intervening tank need to be empty? certifies that the mixture of the contents would not create a fire or a dangerous evolution of heat Q-4 If the answer to Q-1 or Q-2 was No, would there be change to the answer if the shipper or gas? Sincerely Phalat Robert J. Brown, Ji TDA, Inc. PO Box 712 Antioch, California 94509 Ph: (925) 706-0199 fax: (925) 706-0199#