They operate, maintain and adjust boilers, furnaces, engines, pumps, heat exchangers, generators, motors, chillers, cooling towers, including equipment for heating, ventilation, air conditioning, lighting and associated equipment in public buildings, municipal pumping stations and incinerators; make periodic inspections of equipment and minor repairs to such equipment; perform preventive maintenance; take charge of a watch, and while so engaged are responsible for and direct subordinate personnel; may operate control consoles in control rooms; prepare requisitions for materials and spare parts; instruct and train subordinates and other personnel; read meters, gauges, and other recording devices and log the data; keep records and write reports; as directed, inspect low pressure boilers in accordance with a unified inspection procedure instituted by the New York City Department of Buildings; may operate a motor vehicle; and perform related work. Some of the physical activities performed by Stationary Engineers and environmental conditions experienced are: working in confined areas in a physical plant, including a boiler room, heating room, and/or ventilating room; walking up and down stairs; climbing up and down ladders; handling chemicals; and being around hazardous materials, such as asbestos and infectious waste.