Subject to such conditions as the Secretary of State may by regulations prescribe, the provisions of this Part of this Act with respect to general conditions as to hours of employment of women and young persons, notices fixing hours of employment, overtime employment of women and young persons, prohibition of use of rooms during intervals, prohibition of Sunday employment, and annual holidays, shall not apply to male young persons employed as part of the regular maintenance staff of a factory or by a contractor, in repairing any part of the factory or any machinery or plant therein.

No notice shall be required to be served or posted by any occupier availing himself of this exception.