Teachers burned by UV light from cracked halide lamp
9/14/2004

Source: Canadian Occupational Health and Safety News
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September 13, 2004 -- Moosomin, Sask (Canadian OH&S News)--The first day of school was delayed for Moosomin, Sask-area teachers and students when teachers reported sunburn-like symptoms after attending a back-to-school meeting in the McNaughton High School gymnasium.

About 90 teachers from five schools attended the all-day meeting. That evening, 26 teachers, who had been sitting together in a small section of the gym, reported painful rashes, burns, eye irritation and facial swelling. Twenty-two sought medical attention, and six were kept in hospital overnight for observation, says Department of Labour spokesman Dallas McQuarrie.

Classes at McNaughton and MacLeod Elementary, which were scheduled to start September 1, were cancelled pending a health and safety investigation to determine the source of irritation.

Occupational hygienists from the Department of Labour tested air and dust samples when the incident occurred on August 31. But the irritant remained unknown until a maintenance person, who was replacing a metal halide light in the gym, noticed a crack in its outer shell. "One of the lights seemed to be burning at a different colour than the others, so when he changed the light, he noticed the envelope was cracked," says Harold Laich, director of education for Moosomin School District.

McQuarrie says the teachers suffered various degrees of sunburn due to a leakage of UV radiation from the light bulb, comparable to a burn experienced by sitting all day in the sun. The Labour department plans to issue a hazard alert on these bulbs, warning employers of potential UV exposure risks.

In the mean time, Laich says all metal halide lamps at Moosomin District 9 schools have been checked, and will be replaced with safety lamps designed to automatically extinguish the arch tube when the outer envelope is cracked.

The Canadian Centre for Occupational Health and Safety says whether occurring naturally from the sun, or artificially from sources like mercury lamps and welding equipment, UV rays can be hazardous depending on the wavelength, intensity and duration of exposure.

The labour department is continuing its investigation. Classes at the two schools resumed September 3.
(submitted by Tony Moscioni)