Benzene in Drinking Water Information:

Properties:

Benzene is an aromatic hydrocarbon consisting of only carbon and hydrogen atoms that form a single, conjugated ring. It is colourless and has a distinctive odour detectable at concentrations above 10 mg/L.1 In fact, the characteristic odour of petrol can be attributed to the presence of benzene. In addition, benzene is used extensively in chemical production plants and is present in chemicals like DDT, insecticides, and fuels.

Sources:

Benzene can be introduced to drinking water supplies by vehicle emissions, atmospheric deposition, fuel storage tank leaks and industrial processes. It is released almost exclusively through anthropogenic activity; therefore, drinking water sourced from remote locations will be less likely to contain benzene than those near industrial, commercial, or residential centers.2

Regulations:

There is a limit of 1 µg/L (microgram per litre) of benzene allowed in drinking water.

Health/Environmental Concerns:

Benzene is highly toxic. Although liver cells and bone marrow can metabolise and break benzene down, its small size allows it to travel throughout the entire body and be absorbed by skin, the digestive system, and the respiratory system. Exposure to benzene can cause damage to the central nervous system, white blood cells, and other important bodily systems. People exposed to benzene also have an increased risk of developing cancer due to its carcinogenic properties.1

Action:

Because it is unlikely that a consumer would be able to detect low, yet dangerous concentrations of benzene in water by taste or smell, it is important for water providers to protect human health and monitor benzene levels. If levels are found to be in exceedance of limits, contact your Water Service Authority immediately; this normally indicates that there is a spill or leak somewhere upstream of the water supply that must be fixed. The best way to protect drinking water from benzene is eliminating these sources. However, it can also be removed using activated carbon.

(1) Guidelines for Drinking Water Quality. Benzene in Drinking Water; Vol. 2; World Health Organisation: Switzerland, 1996.

(2) Guide to the Parameters in the European Communities. What’s in your water?;  S. I. No. 278 of 2007; National Federation of Group Water Schemes: Ireland.