(a)Adequate. Appropriate and sufficient as determined by mutual
agreement between the manufacturer and MSHA.
(b)Approval. Official notification in writing from MSHA to a
responsible organization, stating that upon investigation its lamp has been
adjudged satisfactory under the requirements of this part.
(c)Explosion-proof compartment. An enclosure that withstands
internal explosions of methane-air mixtures without damage to itself or
discharge of flame and without ignition of surrounding explosive methane-air
(d)Permissible. Completely assembled and conforming in every respect
with the design formally approved by MSHA under this part. (Approvals under
this part are given only to equipment for use in gassy and dusty mines.)
[Sched. 10C, May 17, 1938, as amended by Supp. 1, 20 FR 2718, Apr. 23,