30 C.F.R. § 6.2
The following definitions apply in this part.
Applicant. An individual or organization that manufactures or controls the assembly of a product and applies to MSHA for approval of that product.
Approval. A written document issued by MSHA which states that a product has met the applicable requirements of part 18, 19, 20, 22, 23, 27, 33, 35, or 36. The definition is based on the existing definitions of "approval" in the parts specified above. It is expanded to include "certification" and "acceptance" because these terms also are used to denote MSHA approval.
Approval holder. An applicant whose application for approval of a product under part 18, 19, 20, 22, 23, 27, 33, 35 or 36 of this chapter has been approved by MSHA.
Equivalent non-MSHA product safety standards. A non-MSHA product safety standard, or group of standards, determined by MSHA to provide at least the same degree of protection as the applicable MSHA product approval requirements in parts 14, 18, 19, 20, 22, 23, 27, 33, 35, and 36, or which in modified form provide at least the same degree of protection.
Independent laboratory. A laboratory that:
Post-approval product audit. The examination, testing, or both, by MSHA of approved products selected by MSHA to determine whether those products meet the applicable product approval requirements and have been manufactured as approved.
Product safety standard. A document, or group of documents, that specifies the requirements for the testing and evaluation of a product for use in explosive gas and dust atmospheres, and, when appropriate, includes documents addressing the flammability properties of products.
30 C.F.R. §6.2