15.—(1) Subject to paragraph (2) the Executive may, by a certificate in writing, exempt any person or class of persons or any substance or class of substances from all or any of the requirements or prohibitions imposed by regulations 4 (to the extent permitted by article 9 of Council Directive 98/24/EC), 8, 9, 11(8), (10) and (11) and 14 and any such exemption may be granted subject to conditions and to a limit of time and may be revoked at any time by the Executive by a further certificate in writing.
(2) The Executive shall not grant any such exemption unless having regard to the circumstances of the case and, in particular, to–
(a)the conditions, if any, which it proposes to attach to the exemption; and
(b)any requirements imposed by or under any statutory provisions which apply to the case,
it is satisfied that the health and safety of persons who are likely to be affected by the exemption will not be prejudiced in consequence of it.