||An employer shall ensure that every workplace in his undertaking is ventilated either by natural or mechanical means in such a way that—
||the air breathed by employees does not endanger their safety;
||the time-weighted average concentration of carbon dioxide therein, taken over an eight-hour period, does not exceed one half per cent by volume of air;
||the carbon dioxide content thereof does not at any time exceed three per cent by volume of air;
||the prescribed exposure limits for airborne substances therein are not exceeded; and
||the concentration therein of any explosive or flammable gas, vapour or dust does not exceed the lower explosive limit of that gas, vapour or dust.
||Where the measures prescribed by subregulation (1) are not practicable, or where there is a danger of unsafe air in the breathing zone of an employee, the employer shall provide every such employee with, and ensure that he correctly uses, respiratory protective equipment of a type that reduces the exposure of the employee to a safe level and the employer shall, further, inform him of the dangers of and the precautionary measurers against excessive exposure.
||The provisions of subregulation (1)(b) and (c) shall not apply in respect of workplaces where the ambient pressure differs by more than 20 percent from atmospheric pressure at sea level.
[Regulation 5(3) amended by regulation 3 of Notice No. R. 1754 dated 18 August 1989]