Occupational health and safety act and regulations for construction projects: Revised statutes of Ontario, 1990 Chapter O.1, as amended; O. Reg. 213/91 as amended by O. Reg 631/94, O. Reg.143/99, O. Reg. 571/99, O. Reg. 145/00, O. Reg. 527/00, O. Reg. 85/ by Construction health and safety manual by