Cancer risk warning over candles made from paraffin wax

Burning paraffin wax candles is an unrecognized source of indoor pollution, say scientists.

Levels of chemicals released by candles can build up in unventilated rooms, the American Chemical Society's annual meeting in Washington DC was told.

They include harmful substances such as toluene and benzene – known to cause cancer.

Candle emissions could also irritate the lungs and trigger asthma attacks, said the researchers. And some cases of indoor allergy may actually be a response to inhaling candle fumes, it was claimed.

People who frequently used candles, for instance to help them relax in the bath or provide the right ambience at dinner, were most at risk.

Dr Amid Hamidi, from South Carolina State University in Orangeburg, who co-led the study, said: "An occasional paraffin candle and its emissions will not likely affect you.

"But lighting many paraffin candles every day for years or lighting them frequently in an unventilated bathroom around a tub, for example, may cause problems."

The scientists suggested switching to candles made from beeswax or soy, which were believed to be safer.

To investigate candle emissions, the researchers burned a range of candles in the laboratory and collected the fumes.

These were then analysed in a machine which separated out individual elements and identified them by atomic weight.

Paraffin-based candles produced "clear sharp peaks" for many chemicals as they do not produce high enough temperatures to combust the heavy molecules they contain, the scientists said.