Ozone Hazards From Copy Machines

When it sits in Earth's upper atmosphere, the oxygen-based gas ozone is beneficial since it blocks ultraviolet rays from the sun. However, closer to home, ozone is harmful when inhaled at sufficiently high concentrations and is a component of the toxic air pollution that sometimes plagues large cities. The operation of photocopiers produces ozone, which can cause health problems if allowed to accumulate.

Ozone

• Ozone is a normally colorless gas formed from oxygen. Whereas each molecule of oxygen contains two oxygen atoms, in ozone there are three per molecule. Ozone has a noticeable smell at low concentrations, which is a little like the odor of bleach. It is unstable and reactive, although a small amount is naturally present in the atmosphere, with the largest concentrations in the so-called "ozone layer" in the upper stratosphere. It can be produced through chemical reactions of air pollutants with sunlight and also by electrical discharges in air.

Health Effects

• Ozone is sometimes mistakenly thought of as being healthy, possibly because it is sometimes used as a disinfectant to kill germs. However, this is untrue. Breathing air with appreciable amounts of ozone leads to a number of health problems. Immediate effects include throat and lung irritation, and prolonged exposure can cause permanent reduction in lung function. Individuals with conditions such as asthma or bronchitis can find them made much worse by ozone exposure. Also, some people seem to be more sensitive to ozone exposure and will react to it at lower concentrations. For this reason, it is very hard to pinpoint acceptable levels of ozone exposure, although levels around 200 micrograms per cubic meter of air appear to cause some health effects.

Copier Emissions

• Copiers rely on an process where a static electric charge causes toner to adhere to a printing unit in certain areas. This charging process, as well as ultraviolet emissions from the copier lamp, produces ozone from local atmospheric oxygen. The average amount of ozone produced is about 40 micrograms per copy. Compare this to the level of 200 micrograms per cubic meter of air at which health problems appear, and you can see that making multiple copies could easily exceed this level in the copier's immediate vicinity.

Safe Use of Copiers

• There are several things you can do to reduce the hazards of ozone generated by copiers. For one thing, the copier should be placed in a room with good ventilation: either open windows or frequent air exchanges. Personnel should not be working in close proximity to a copier. Since newer copiers are designed to reduce ozone emissions, an older machine can be traded in for a safer model. Also, the use of other chemicals in the office, such as cleaning products, should be minimized to reduce reactions of these compounds with ozone, which can form irritants.