Passive Failure – Why do some of my (metal halide) lamps burst during operation?
Most metal halide lamps will not fail this way if operated according to the lamp manufacturer’s instructions, but there is always the possibility. The likelihood of a non-passive failure is increased if the lamps are operated round the clock and not powered off at least once a week. The reason that the lamp can fail this way is inherent in their design. The center arc tube is made of quartz.
