Section 204(a) in U.P. Building And Other Construction Workers (Regulation Of Employment And Conditions Of Service) Rules, 2009
(a)every working chamber at an excavation or tunneling work where compressed air is used the supply of such air is maintained not less than 0.30 cubic meter per minute per person working therein and such air is, as far as practicable be free from dust, fumes and other toxic substances;
