30 CFR §44.4

1. (a)A petition for modification of application of a mandatory safety standard may be granted upon a determination that—
   1. (1)An alternative method of achieving the result of the standard exists that will at all times guarantee no less than the same measure of protection afforded by the standard, or
   2. (2)Application of the standard will result in a diminution of safety to the miners.
2. (b)Except as may be provided in § 44.16 for relief to give effect to a proposed decision and order, a decision of an Administrator or an administrative law judge granting or denying a petition for modification shall not be effective until time for appeal has expired under § 44.14 or § 44.33, as appropriate.
3. (c)All petitions for modification granted pursuant to this part shall have only future effect: Provided, That the granting of the modification under this part shall be considered as a factor in the resolution of any enforcement action previously initiated for claimed violation of the subsequently modified mandatory safety standard. Orders granting petitions for modification may contain special terms and conditions to assure adequate protection to miners. The modification, together with any conditions, shall have the same effect as a mandatory safety standard.