Chemical in Computer Monitors Triggers Allergies, Illness

By Cat Lazaroff

WASHINGTON, DC, September 19, 2000 (ENS) - Computer workers who suffer from headaches may have more than eye strain to blame. New research suggests that emissions from the plastic of computer video monitors may affect workers’ health.

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Computer users may be exposed to chemicals that leach from their monitors, a new study shows (All photos by Warren Gretz, courtesy National Renewable Energy Laboratory)
A Swedish study presented in the September 15 edition of "Environmental Science & Technology," a peer reviewed journal of the American Chemical Society, shows that triphenyl phosphate can cause allergic reactions in some people. The reactions can range from itching and nasal congestion to headaches.

Triphenyl phosphate is a chemical compound widely used as a flame retardant in the plastic of video monitors and other products.

Computer monitors emit the compound when their temperature rises during normal operations, said Conny Ostman, lead author of the study, from Stockholm University in Sweden. It is unknown how much exposure can cause an allergic reaction, he added.

What is known is that new computers emit more of the compound than older ones.

"We have focused our interest on this compound since it has been proven to be a contact allergen to man and due to the fact that a number of workers in Sweden have acquired health problems related to computer work," Ostman said.

The researchers measured the level of the compound in the "breathing zone," located about two feet in front of the video screen. Temperatures of the operating monitors ranged between 122 degrees and 131 degrees Fahrenheit.

The researchers tested the bodies of computers as well, but found they contained no significant amounts of the compound.

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Emissions of triphenyl phosphate decline with use, but remain 10 times higher than background levels even after two years of working computer use
The emissions levels dropped sharply after eight days of continuous operation, the researchers found, but remained 10 times higher than the background level even after 183 days - roughly the equivalent of about two years of working use.

Computers are a significant source of allergenic emissions in small indoor environments like offices, Ostman said. Even with adequate ventilation, the compound may be a potential health hazard for computer users, he warned.

The researchers found appreciable concentrations of the compound in 10 of the 18 brand new video monitors they tested.

Ostman declined to name their manufacturer, saying that almost all manufacturers use the same flame retardant compound. The presence and levels of triphenyl phosphate in monitors varied with the place where they were manufactured, he explained.

The U.S. Occupational Safety and Health Administration sets a safety limit of three milligrams per cubic meter of air for triphenyl phosphate, noting that it can cause changes in blood enzymes in humans. The chemical is also classified as causing "occupational allergic contact dermatitis."

A concentration of 1,000 milligrams per cubic meter of air is listed as "immediately dangerous to life or health" by the National Institute of Occupational Safety and Health.

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The hotter the computer monitors get, the more triphenyl phosphate is emitted by their plastic covers
The U.S. Geological Survey monitors for triphenyl phosphate in water because it is classified as an "emerging contaminant," one whose environmental or health risks are suspected but not confirmed.

Besides its use in plastic products, triphenyl phosphate is also an ingredient in some pesticides.

U.S. state and federal agencies monitor for triphenyl phosphate in groundwater and soil, noting that it can leach from landfills and abandoned industrial sites.