Section 243(a) in U.P. Building And Other Construction Workers (Regulation Of Employment And Conditions Of Service) Rules, 2009
(a)When an internal combustion engine exhausts into a confined space or excavation or tunnel or any other workplace where neither natural ventilation nor artificial ventilation system is adequate to keep the carbon monoxide content of atmosphere below fifty parts per million, adequate and suitable measures are taken at such workplace in order to avoid exposure of building workers to health hazards;
