An employer or self-employed person shall ensure that-
(a) all control equipment and facilities provided in terms of regulations 11, 12, and 13 are maintained in good working order; and
(b) examinations and tests of engineering control measures are carried out at intervals not exceeding 24 months by an approved inspection authority approved for such examinations and tests or by a person whose ability to do the measurements and tests is verified by such an approved inspection authority.