Clause 12

by deleting subsection (1) thereof and substituting therefor the following: —“(1) Where, in connection with any process giving rise to dust, gas, vapour or substance, there may escape into any workplace dust, gas, vapour, or substance, of such a character and to such an extent as to be liable to explode on ignition, all practical steps shall be taken to prevent such an explosion —

by enclosure of the plant used in the process;

by removal or prevention of accumulation of the dust, gas, vapour or substance;

by exclusion or effective enclosure of possible sources of ignition; and

by the use of suitable flame-proof equipment.”;

by inserting immediately after subsection (4) thereof the following new subsections: —“(5) No plant, tank or vessel which contains, or has contained, any explosive or inflammable substance shall be subjected to any of the operations referred to in paragraph (a), (b) or (c) of subsection (4) of this section unless such plant, tank or vessel has been inspected and certified by a competent person —

to be free from any explosive or inflammable substance or from any fumes arising from any such substance, or that the substance or any fumes arising from it have been rendered non-explosive or non-inflammable; and

that it is safe for any such operations to be carried out.(6) Any certificate issued by a competent person pursuant to subsection (5) of this section shall be kept available at all times for inspection by an inspector.”; and

by renumbering the existing subsection (5) thereof as subsection (7).