“A romantic candle-lit dinner can give you cancer”, according to the Daily Mail. The newspaper says that, while candles can add a hint of romance to a meal or make taking a bath a real luxury, the smoke produced by many “is laced with toxins linked to cancer, asthma and eczema”.

Several other newspapers have picked up on a piece of research presented at the 238th National Meeting of the American Chemical Society (ACS) this week. The presentation suggests that burning candles made from paraffin wax is an “unrecognised source of exposure to indoor air pollution”.

The research behind the news and presentation has not yet been published, so a full appraisal of its quality is not possible at this time. It appears that this news has come from brief press releases and a presentation abstract that feature details on a comparison carried out between beeswax and paraffin wax candles.

 

What is the basis for these current reports?

Online press releases from EurekAlert! and National News mention research carried out at the South Carolina State University and orally presented at the 238th National Meeting of the American Chemical Society (ACS). Limited information is given about the methods of the study that underlies these claims.

According to the National News press release, researchers burned paraffin candles for about five or six hours. They found that the candles produced chemicals that are “harmful” and potentially carcinogenic. News reports say that candles made from beeswax or soy are safer, but it is also unclear how the researchers tested these.

Among the gases produced by paraffin-based candles, the researchers apparently found specific chemicals that have been linked to cancer, such as formaldehyde. However, there is not enough information about the results of this study to have a sensible discussion about whether the doses or types of chemical produced are a cause for concern.

 

What did the scientists do?

The scientists set out to investigate the chemical emissions from burning paraffin wax candles made by different manufacturers. They burnt the candles in a chamber (8 x 8 x 26 inches) which pumped the gases into a glass ampoule containing highly absorbent activated coconut charcoal.

After five to six hours of burning, the contents of the ampoule were analysed using a type of mass spectrometer that precisely identifies the chemical constituents of the gases. The paraffin-based candles produced clear sharp peaks indicating the presence of many products such as toluene, alkanes and alkenes, as well as some ketones and aldehydes. The scientists say their “results proved largely reproducible”.

 

How does this research affect me?

Until this research is published in a journal it is not possible to scrutinise the methods used and to establish how relevant its findings are to human health. It is possible that the study may never be published, as a great deal of research presented at conferences does not make it into peer-reviewed journals.

The abstract available does not describe any comparisons with beeswax candles, so it is not possible to say what the fumes from beeswax candles contain. The levels of gaseous chemical emissions from the paraffin-based candles are also not given, so relating these findings to any minimum safety levels is not possible.

One of the researchers has been quoted as saying that, “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 un-ventilated bathroom around a tub, for example, may cause problems”.

Several cancer experts have offered their opinions on these findings. Dr Joanna Owens, science information manager at Cancer Research UK, said that, "when talking about cancer risk, it's important to focus on things we have hard evidence for. There is no direct evidence that everyday use of candles can affect our risk of developing cancer.

“In terms of cancer, a far more significant type of indoor air pollution is secondhand cigarette smoke. Lifestyle factors such as smoking, alcohol, obesity, unhealthy diets, inactivity and heavy sun exposure account for a much larger proportion of cancers."

Dr Noemi Eiser, Honorary Medical Director of the British Lung Foundation, said, "We would like to reassure people that occasional use of paraffin candles should not pose any risk to their lung health.
 
"However, we would advise people to take sensible precautions when burning candles, such as opening a window to keep the room ventilated to minimise the amount of emissions breathed in."

Links To The Headlines

Romantic candles could cause cancer, say scientists. The Daily Telegraph, August 20 2009

How a romantic candle-lit dinner can give you cancer. Daily Mail, August 20 2009

Candle-lit dinners 'can cause cancer'. The Metro, August 20 2009

CANDLES CANCER. Daily Star, August 20 2009