Hazardous location lighting fixtures illuminate areas with flammable, combustible, or ignitable materials. Also known as hazloc lights, they keep arcs and sparks contained so that the fixtures won't cause a fire or explosion. They carry class and division ratings as defined by NEC and OSHA for use in locations where specific hazards are present in normal or abnormal conditions. Class I and II fixtures also carry group ratings designating use in locations with specific types of gas, vapor, or dust. Round fixtures have a compact footprint and a traditional jelly jar look. Linear fixtures have a long body to spread light over a wide area. Square fixtures deliver high-output light from high ceilings. Signal and warning lights mark restricted areas or alert people to nearby hazards. Emergency and exit lights turn on during power outages to guide evacuations from buildings. Retrofit kits convert existing hazloc fixtures to LED, reduce operating costs, and improve light quality.