For the purpose of giving guidance on appropriate methods (including the use of specified types of plant or machinery) for minimising noise, the Secretary of State may—
(a) prepare and approve and issue such codes of practice as in his opinion are suitable for the purpose; and
(b) Approve such codes of practice issued or proposed to be issued otherwise than by the Secretary of State as in the opinion of the Secretary of State are suitable for the purpose.
The Secretary of State shall under paragraph (a) or paragraph (b) of the preceding subsection approve a code of practice for the carrying out of works to which section 60 of this Act applies.
The powers conferred by this section on the Secretary of State shall be exercisable by order, and shall include power to vary or revoke a previous order under this section.