30 CFR §28.25

1. (a)Each applicant may, if he desires to change any feature of an approved fuse, request a modification of the original certificate of approval issued by MSHA for such fuse by filing an application for modification in accordance with the provisions of this section.
2. (b)Applications, including fees, shall be submitted as specified in § 28.10 for an original certificate of approval, with a request for a modification of the existing certificate to cover any proposed change.
3. (c)The application for modification, together with the examination, inspection, and test results prescribed by § 28.10 shall be examined and evaluated by MSHA to determine if the proposed modification meets the requirements of this part.
4. (d)If the proposed modification meets the requirements of this part, a formal modification of approval will be issued, accompanied, where necessary, by reproductions of revised approval labels or markings.