30 CFR 22.11 - Instructions on handling future changes in design.
All approvals are granted with the understanding that the manufacturer will make the detector according to the drawings submitted to MSHA which have been considered and included in the approval. Therefore, when the manufacturer desires to make any changes in the design, the manufacturer should first obtain MSHA's approval of the change. The procedure is as follows:
(1) The manufacturer must write to the U.S. Department of Labor, Mine Safety and Health Administration, Approval and Certification Center, 765 Technology Drive, Triadelphia, WV 26059, requesting an extension of the original approval and stating the change or changes desired. With this request, the manufacturer should submit a revised drawing or drawings showing changes in detail, together with one of each of the parts affected.
(2) Where the applicant for approval has used an independent laboratory under part 6 of this chapter to perform, in whole or in part, the necessary testing and evaluation for approval of changes to an approved product under this part, the applicant must provide to MSHA as part of the approval application:
(i) Written evidence of the laboratory's independence and current recognition by a laboratory accrediting organization;
(ii) Complete technical explanation of how the product complies with each requirement in the applicable MSHA product approval requirements;
(iii) Identification of components or features of the product that are critical to the safety of the product; and
(iv) All documentation, including drawings and specifications, as submitted to the independent laboratory by the applicant and as required by this part.
(b) MSHA will consider the application and inspect the drawings and parts to determine whether it will be necessary to make any tests.
(c) If no tests are necessary, the applicant will be advised of the approval or disapproval of the change by letter from MSHA.
(d) If tests are judged necessary, the applicant will be advised of the material that will be required.