This topic studies the structure and mode of occupational health and safety management system and environmental management system. The core elements include the following 10 elements: occupational health and safety policy; Identification of hazard sources, risk assessment and determination of control measures; Laws, regulations and other requirements; Objectives and programmes; Resources, roles, responsibilities, responsibilities and authorities; Compliance assessment; Operational control; Performance measurement and monitoring; Internal audit; Management review. Options b, c and d are auxiliary elements.