30 CFR § 20.13 - Approval plate.
The manufacturer shall attach, stamp, or mold an approval plate on the battery container or housing of each permissible lamp. The plate shall bear the emblem of the Mine Safety and Health Administration, and be inscribed as follows: “Permissible _____ Lamp. Approval No. __________ issued to the __________ Company.” When deemed necessary, an appropriate caution statement shall be added. The size, material, and position of the approval plate shall be satisfactory to MSHA.
(a) Purpose of approval plate. The approval plate is a label which identifies the lamp so that anyone can tell at a glance whether the lamp is of the permissible type or not. By it the manufacturer can point out that his lamp complies with specifications of MSHA and that it has been adjudged safe for use in gassy and dusty mines.
(b) Use of approval plate. Permission to place MSHA's approval plate on his lamp obligates the manufacturer to maintain the quality of his product and to see that each lamp is constructed according to the drawings which have been accepted by MSHA for this lamp and which are in the MSHA files. Lamps exhibiting changes in design which have not been approved are not permissible lamps and must not bear MSHA's approval plate.
(c) Withdrawal of approval. MSHA reserves the right to rescind for cause at any time any approval granted under this part.