30 CFR § 18.15
Changes after approval or certification.
If an applicant desires to change any feature of approved equipment or a certified component, he shall first obtain MSHA's concurrence pursuant to the following procedure:
(a)(1) Application shall be made as for an original approval or letter of certification requesting that the existing approval or certification be extended to cover the proposed changes and shall be accompanied by drawings, specifications, and related information, showing the changes in detail.
(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 or certified 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.
[43 FR 12313, Mar. 24, 1978, as amended at 52 FR 17514, May 8, 1987; 68 FR 36420, June 17, 2003]