Benzene

Benzene is a chemical compound of carbon and hydrogen which is a colourless clear liquid at ambient temperatures. It is fairly stable but will readily evaporate.

In the UK, the majority of benzene emissions originate from un-burnt fuel in petrol vehicle exhaust gases and fuel evaporation during refuelling as well as from the burning of coal and oil and industrial solvent use. Tobacco smoke contains benzene and accounts for nearly half the national exposure to benzene.

Benzene is accepted as a human carcinogen. Occupational studies have shown that long-term exposure to significant concentrations may be associated with leukaemia. The Department of the Environment, Transport and the Regions (now DEFRA), recommended an air quality standard of 5 parts per billion (ppb) for benzene as an annual mean,.

Poisoning occurs most commonly through inhalation of vapour, however it can penetrate the skin. Locally benzene has quite a strong irritant effect, producing erythema and burning. In more severe cases it can cause edema and blistering.

In chronic poisoning the onset is slow. The symptoms include fatigue, headaches, dizziness, nausea and loss of appetite, loss of weight and weakness are common complaints in early cases.

Benzene has a cumulative effect and repeated exposure can cause mounting damage.