Transportation Systems Solutions — Hazardous Materials Safety Interpretation

Page 1400 Seventh Street, S.W. Washington, D.C. 20590 Pipeline and Hazardous Materials Safety SEP 15 2006 Administration Mr. Peter Olsen Transportation Systems Solutions Ref. No. 06-0155 318 Hampshire Lane Crystal Lake, Illinois 60014 Dear Mr. Olsen: This is in response to your June 27, 2006 letter requesting clarification of the Hazardous Hazard Division 5.1 Oxidizers. Your questions are paraphrased and addressed as follows: Materials Regulations (HMR; 49 CFR Parts 100-180) applicable to testing criteria for Q1. Is a material that does not meet the definition of an "Oxidizer" as specified under § 173.127 of the HMR when it is transported in a solid tablet form required by the to conduct the oxidizer test? United Nations (UN) Manual for Test and Criteria to be ground to a powder form Al. As specified in § 173.127 of the HMR, a solid material is classed as a Division 5.1 material (Oxidizer) if, when tested in accordance with the UN Manual o: Tests and potassium bromate/cellulose mixture. The UN Manual of Tests and Criteria Criteria, its mean burning time is less than or equal to the burning time cf a 3:7 specifies that tests are conducted on the substance to be evaluated mixed with dry fibrous cellulose in mixing ratios of 1:1 and 4:1, by mass, of sample to cellulose. The UN Manual of Tests and Criteria also specifies that a substance, in the form in in diameter. If that powder constitutes more than 10% (mass) of the total, or if the which it will be transported, should be inspected for any particles less than 500 um substance is friable, then the whole of the test sample should be ground to a powder before testing to allow for a reduction in particle size during handling and transport. In addition, the UN Manual for Tests and Criteria specifies that, as the particle size for a solid substance to increase the burning rate or burning intensity of a has a significant effect on the result of the test performed to determine the potential combustible material, the particle size of the substance should be stated in the test report. Q2. If the material that has been ground to a powder form meets the definition of an "Oxidizer," does the UN Manual for Tests and Criteria allow for a specific percentage of the powder to be generated from the tablet form? A2. See response above. 173.127 060155#

Page 2Q3. Is there a grain size limit for the powder of the above material generated before the tablets would be considered an "Oxidizer" under § 173.127? A3. See response above. I trust this satisfies your inquiry. Sincerely, / Chief, Standards Development Office of Hazardous Materials Standards#

Page 3Foster $173.127 (g() Detinition Transportation Systems Solutions 06-0154 318 Hampshire Lane - 0/55 Crystal Lake 815-479-0897 Illinois, 60014 U.S Department of Transportation Pipeline and Hazardous Materials Safety Administration 400 7° St S.W Office of Hazardous Materials Safety Washington, DC 20590-0001 Dear Sir/Madam, Transportation Systems Solutions (TSS) respectfully seeks an interpretation as e solid oxidizer in question is in a solid tablet form for transportation purpose nd when in this solid tablet form it does not meet the definition of an oxidizer a defined in 49 CFR 172.127 is it required that this tablet be ground to a powder form to conduct the oxidizer test? Given that if the solid tablet is ground to a • powder that it does meet the definition for an oxidizer TSS respectfully asks does he UN Manual for Test and Criteria allow for a certain percentage of powder to for the powder generated before the tablets would have to be considered an oxidizer by definition? packaged in an impervious plastic liner in a strong outer packaging such that any The solid tablets in question, that do not meet the definition of an oxidizer, are powder generated during transport would not be released. I thank you for your assistance in this matter and look forward to your response.#