 The glass bulb of a general service lamp can reach temperatures between .Lamps intended for high power operation or used for heating purposes will have envelopes made of hard glass or fused quartz.If a light bulb envelope leaks, the hot tungsten filament reacts with air, yielding an aerosol of brown tungsten nitride, brown tungsten dioxide, violet-blue tungsten pentoxide, and yellow tungsten trioxide that then deposits on the nearby surfaces or the bulb interior.