More than half of new computer monitors currently being sold are treated with a flame-retardant chemical known for provoking allergic reactions. The compound, triphenyl phosphate (TP), is emitted from the screen into the air when heated up as a result of everyday usage.

The study authors report that "use of this compound as an additive in VDU (video display unit) covers may be considered as a risk to human health."

Researchers performed two studies examining the effect of short-term and long-term computer usage on emissions of this chemical.

• The investigators gathered 18 brand-new computer VDUs from seven different models manufactured by a major international computer company.

• They then extracted sample levels of TP, from the computers as well as the air surrounding them.

• Emission levels were measured after turning on the monitors for periods ranging from 1 day to 183 days.
  

• Researchers found no TP in the plastic material of the main chassis and circuit board of any of the computers, they did detect TP in 10 out of the 18 VDUs.

Researchers found that when the computers are in operation even for as little as 1 day, the temperature of the screens mounts to between 122 and 131 degrees Fahrenheit, at which point the TP is released into the air.

Although emission levels dropped by almost half after a week of continuous usage, the levels within the 2-foot area in front of the computer screen, labeled the "breathing zone," were still 10 times as high as the surrounding office air even after 183 days, the report indicates.

Aside from computer screens, this flame retardant is commonly used in a wide range of commercial products including:

• TV sets and other electronic goods
  

• Varnishes
  

• Lubricants
  

• Plastic

As for dealing with the problems associated with what is now a common part of most modern office environments and often the home as well, the researchers have no complete remedy. They suggest, however, that the best method of minimizing the potential allergic effects of such emission would be to "bake out" the TP chemical by turning on a new VDU for 10 days before initial use, a step which could potentially reduce the concentration of the chemical by two-thirds within the breathing zone.

Environmental Science and Technology September 15, 2000;34:3885-3889