Subject to the provisions of this section, no lamps or lights other than permitted lights shall be allowed or used below ground in a mine of coal first opened on or after the date of the commencement of this Act.
Subject to the provisions of this section, no lamps or lights other than permitted lights shall be allowed or used below ground in a mine (whether of coal or of any other mineral) first opened before the said date, being either—
a mine in the case of which, immediately before that date, the use below ground therein of lamps or lights, other than locked safety-lamps or some other means of lighting the use of which below ground therein was authorised by or under the enactments repealed by this Act, was unlawful or would have been unlawful but for an exemption then in force ; or
a mine (other than as aforesaid) in the case of which locked safety-lamps were being used below ground therein immediately before that date otherwise than by way of temporary precaution.
Subject to the provisions of this section, no lamps or lights other than permitted lights shall, in the case of a mine (whether of coal or of any other mineral) first opened before the said date (not being a mine to which subsection (2) of this section applies) or of a mine other than of coal first opened on or after the said date, be allowed or used below ground after—
the occurrence in any part of the mine below ground of an ignition or explosion of gas naturally present in the mine (whether or not causing death or bodily injury); or
the introduction of the use, in any part of the mine below ground, of locked safety-lamps otherwise than by way of temporary precaution ; or
the expiration of the period of four weeks beginning with the day next following that on which there has become operative a notice served on the manager of the mine by an inspector stating that he is of opinion that no lamps or lights other than permitted lights ought to be used below ground in the mine.
Such a notice as is mentioned in paragraph (c) of the last foregoing subsection shall not be served otherwise than in a case where inflammable gas is known to have been naturally present in the mine to which it relates at some time during the period of five years ending with the date on which service is effected, and the provisions of Part XV of this Act with respect to references upon notices served by inspectors shall apply to any such notice.
If an inspector is satisfied with respect to a mine or a part of a mine that, by reason of the special character of the mine or part, compliance with the requirements of the foregoing provisions of this section is unnecessary, he may, by notice served on the manager of the mine, exempt the mine or part from those provisions:
Provided that no exemption from the said provisions of a part of a mine of coal shall be granted after the expiration of the period of four years beginning with the commencement of this Act or shall be granted or renewed before the expiration of that period otherwise than so as to expire not later than the expiration of that period.