An employer shall ensure at a construction site of a building or other construction work that,—
(a) when an internal combustion engine exhausts harmful emissions within the prescribed limits into a confined space or excavation or tunnel or any other work place, where neither natural ventilation nor artificial ventilation system is found adequate to keep the contents of the atmosphere below fifty parts per million, adequate and suitable measures are taken at such work place in order to avoid exposure of building workers to health hazardous or alternative mode of power shall be used;
and Section 40 (2) (g)Section 40 (2) (g) 13
(b) no building worker or unauthorised person is allowed to enter into any confined space, well, tank, trench or excavation wherein there is given off dust, fumes or other impurities of such a nature and to such an extent, as are likely to be injurious or offensive to the building worker or in which explosives, poisonous, noxious, gaseous material or other harmful particles, which have been carried or stored or in which dry ice has been used as a refrigerant, or which has been fumigated or in which there is a possibility of oxygen deficiency, unless all practical steps like exhaust fans etc. have been taken to remove such dust, dangerous fumes, or other impurities, which may be present, and before any ingress into such confined space, well, tank, trench or excavation, it is certified by the responsible person that such work place is safe and fit for the entry of the building workers.