30 CFR § 75.501
Permissible electric face equipment; coal seams above water table.
On and after March 30, 1974, all electric face equipment, other than
equipment referred to in paragraph (b)
, which is taken into and used inby the last
open crosscut of any coal mine which is operated entirely in coal seams
located above the water table and which has not been classified under any
provision of law as a gassy mine prior to March 30, 1970, and in which one or
more openings were made prior to December 30, 1969, shall be permissible.