Most projector bulbs (lamps) contain highly pressurized chemicals that ignite to create a very bright, energy efficient light output. One of the chemicals used to manufacture projector bulbs is Mercury , which is an extremely toxic heavy metal .
Dangers of Mercury :
The use of toxic materials in household items is decreasing. Remember : old thermometers contained Mercury, but newer thermometers now contain another substance (usually a red tinted alcohol) that is safer.
However, when toxic chemicals are used, as is the case with these projector bulbs, we must dispose of them properly to prevent environmental contamination .