Section 15.4 - Application procedures and requirements(a)Application. Requests for an approval or an extension of approval under this part shall be sent to: U.S. Department of Labor, Mine Safety and Health Administration, Approval and Certification Center, 765 Technology Drive, Triadelphia, WV 26059.(b)Fees. Fees calculated in accordance with Part 5 of this Title shall be submitted in accordance with § 5.40 .(c)Original approval for explosives. Each application for approval of an explosive shall include-(1) A technical description of the explosive, including the chemical composition of the explosive with tolerances for each ingredient;(2) A laboratory number or other suitable designation identifying the explosive. The applicant shall provide the brand or trade name under which the explosive will be marketed prior to issuance of the approval;(3) The lengths and diameters of explosive cartridges for which approval is requested;(4) The proposed minimum product firing temperature of the explosive; and(5) The name, address, and telephone number of the applicant's representative responsible for answering any questions regarding the application.(d)Original approval for sheathed explosive units. Each application for approval of a sheathed explosive unit shall include-(1) A technical description of the sheathed explosive unit which includes the chemical composition of the sheath, with tolerances for each ingredient, and the types of material used for the outer covering;(2) The minimum thickness weight, and specific gravity of the sheath and outer covering;(3) The brand or trade name, weight, specific gravity, and minimum product firing temperature of the approved explosive to be used in the unit;(4) The ratio of the weight of the sheath to the weight of the explosive; and(5) The name, address and telephone number of the applicant's representative responsible for answering any questions regarding the application.(e)Subsequent approval of a similar explosive or sheathed explosive unit. Each application for approval of an explosive or sheathed explosive unit similar to one for which the applicant already holds an approval shall include-(1) The approval number of the explosive or sheathed explosive unit which most closely resembles the new one;(2) The information specified in paragraphs (c) and (d) of this section for an original approval, as applicable, except that any document which is the same as the one listed by MSHA in the prior approval need not be submitted but shall be noted in the application; and(3) An explanation of all changes from the existing approval.(f)Extension of the approval. Any change in an approved explosive or sheathed explosive unit from the documentation on file at MSHA that affects the technical requirements of this Part shall be submitted for approval prior to implementing the change.(1) Each application for an extension of approval shall include-(i) The MSHA-assigned approval number for the explosive or sheathed explosive unit for which the extension is sought;(ii) A description of the proposed change to the approved explosive or sheathed explosive unit; and(iii) The name, address, and telephone number of the applicant's representative responsible for answering any questions regarding the application.(2) MSHA will determine what tests, additional information, samples, or material, if any, are required to evaluate the proposed change.(3) When a change involves the chemical composition of an approved explosive or sheathed explosive unit which affects the firing characteristics, MSHA may require the explosive or sheathed explosive unit to be distinguished from those associated with the former composition.53 FR 46761, Nov. 18, 1988; 54 FR 351, Jan. 5, 1989; 60 FR 33723, June 29, 1995; 73 FR 52211, Sept. 9, 2008