Section 30: Precautions with respect to explosive or inflammable dust, gas, vapour or substance.

(1) Where in connection with any grinding, sieving or other process giving rise to dust, gas or vapour there may escape into any workroom dust, gas or vapour of such a character and to such an extent as to be liable to explode on ignition, all practicable steps shall be taken to prevent such an explosion by enclosure of any plant used in the process, and by removal or prevention of accumulation of the dust, gas or vapour and by exclusion or effective enclosure of possible sources of ignition.
(2) Where there is present in any plant used in any such process as aforesaid dust, gas or vapour of such a character and to such an extent as to be liable to explode on ignition, then, unless the plant is so constructed as to withstand the pressure likely to be produced by any such explosion, all practicable steps shall be taken to restrict the spread and effects of such an explosion by the provision, in connection with the plant, of chokes, baffles and vents or other equally effective appliances.
(3) No plant, tank or vessel which contains or has contained any explosive or inflammable substance shall be subjected to any welding, brazing or soldering operation or to any cutting operation which involves the application of heat, until all practicable steps have been taken to remove the substance and any fumes arising therefrom or to render them non-explosive or inflammable; and if any plant, tank or vessel has been subjected to any such operation as aforesaid, no explosive or inflammable substance shall be allowed to enter the plant, tank or vessel until the metal has cooled sufficiently to prevent any risk of igniting the substance
(4) The Director of Factories may by certificate in writing grant, subject to any conditions specified in the certificate, exemption from compliance with any of the requirements of subsection (3) of this section where he is satisfied that compliance with the requirements is unnecessary or impracticable.