Signal and warning lights are visual indicators that mark restricted areas, call attention to non-functioning machinery, or alert people to nearby hazards in locations with flammable, combustible, or ignitable materials. These hazloc lights 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. LED signal flashers provide a longer service life than xenon flashers. Xenon signal flashers produce shorter but more intense light bursts than LED flashers.