Clause 4

Effective and suitable provision shall be made for securing and maintaining by the circulation of fresh air in each workplace, adequate ventilation of the workplace and for rendering harmless, so far as practicable, all such fumes, dust and other impurities generated in the course of any process or work carried out in the factory as may be injurious to health.(2) The provisions of subsection (1) of this section shall not apply to any workplace where it is impracticable to make provision for adequate ventilation and where breathing apparatus is used by persons working in the workplace.”.