Dangers and effects of Metal Halide on humans

**Shadow** · 14th Oct 2008, 13:21

Didn't know that MH can be dagerous to human until I read on wikipedia

http://en.wikipedia.org/wiki/Metal_halide_lamp

Dangers and effects on humans
Eyes
Although an excellent source of lighting for the reef aquarium, there has been concern voiced by some aquarists over the potential ill-effects of close-range contact with metal halide lighting which is demanded by the hobby. Some individuals have noticed temporary blurred vision even after very brief exposure to metal halide lighting. This blurring of vision could be linked to Photokeratitis (snow blindness) - the result of unprotected exposure to Ultraviolet (UV) radiation.

FDA cautions
Broken and unshielded high intensity metal halide bulbs could cause eye and skin injuries, particularly in school gymnasiums. See the following article from the FDA: / Ultraviolet Radiation Burns from High Intensity Metal Halide and Mercury Vapor Lighting Remain a Public Health Concern Also see: / Teachers battle dangerous lighting conditions and / Photokeratitis and UV-Radiation Burns Associated With Damaged Metal Halide Lamps

Explosion Hazard
Metal Halide Lamps of the quartz arc tube variety are susceptible to explosion at the end of their rated life due to the corrosive effects of the halide salts on the quartz. Burning universal position lamps horizontally also increases risk of explosion due to higher arc wall temperature. Mechanical shock such as vibration may also cause explosion, as may leaving the lamp on all day. As such, metal halide fixtures should be turned off at least 15 minutes each week to reduce explosion hazard, and a quartz shroud may also be added for further protection and to reduce halide ions migrating through the arc tube wall (quartz metal halide lamps only).