Most fluorescent lamps and High Intensity Discharge (HID) lamps use mercury. The mercury is in vapor form, and is essential in emitting the ultraviolet light that makes fluorescent and HID lamps glow. Lamps that use mercury include common fluorescent lamps, metal halide lamps and high-pressure sodium lamps used for floodlights and streetlights.
Because mercury can be extremely harmful to humans and the environment, large quantities of waste mercury-containing lamps are managed under the University's Mercury-Containing Lamp Program. This plan was developed in accordance to the city of Evansville's universal waste and hazardous waste regulations.