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Indoor Air Quality
Scented candle fumes 'as toxic as cigarettes' (#2002)
Few homes are without the wafting perfume of a scented candle from time to time. We light them to infuse a room with fragrance, to add a romantic ambiance to a meal and to make bath times more luxurious.
But could the very candles used to soothe our mood actually be bad for us?
Research has shown some scented candles produce smoke laced with almost as many toxins as those produced by cigarettes.
This unit is designed to treat volatile organic compounds, odors and other airborne pollutants. It features a special carbon blend and a HEPA filter for particles.
Since they are often lit in poorly ventilated rooms, such as bathrooms, or during the evening when windows are likely to be closed, the release of chemicals can cause indoor pollution that is potent enough to raise the risk of asthma, eczema and skin complaints.
Sales of scented candles have soared in recent years as they have come to represent the ultimate fulfillment of ‘me’ time.
More expensive varieties made from beeswax and soy rarely cause problems, but the majority of those sold in the UK are cheap imports made from paraffin wax, a by-product of the petroleum industry.
These have been shown to release an alarming range of volatile organic compounds (VOCs), substances that can be problematic to health.
When U.S. researchers burnt a range of candles in a laboratory for a study published two years ago, the chemicals released in harmful amounts included human carcinogens and chemicals known to cause asthma attacks, such as toluene and benzene.
Dr Amid Hamidi of South Carolina University, who led the study, showed that paraffin-based candles produced ‘clear sharp peaks’ for many chemicals, mainly because they do not reach high enough temperatures when being burned to destroy the hazardous molecules they emit.
‘An occasional paraffin candle and its emissions will probably not affect you,’ he said. ‘But lighting many of them every day for years, or lighting them frequently in an unventilated bathroom, for example, may cause problems.’
It’s not just the candle wax that is potentially dangerous. Many of the mass-market products contain synthetic fragrances and sometimes dyes that can give off harmful particles when they are heated.
Then there are the hazards of wicks. A non-cored wick, made from braided or twisted fibre, is considered the safest to burn, but can be limp and fall over in the wax, extinguishing a flame.
Many candle makers use a cored wick, in which cotton is wrapped around a metal or paper core for support.
Like anything that burns, once a candle is lit it produces soot, with particles that can remain suspended in the air for several hours.
Research by the U.S. Environmental Protection Agency has shown scented candles give off more of this soot than unscented, and that cored candles release the dirtiest soot — sometimes containing particles of zinc, tin, lead and the metal cadmium.
In a laboratory analysis of candles conducted for consumer magazine Proof!, the smoke from pillar-type candles and tea lights purchased from supermarkets and department stores in London was analyzed for traces of cadmium and lead.
Almost one fifth of those tested had detectable levels of cadmium and a small number released lead.
More alarming were the findings from a study by Dutch scientists, who measured the air particles in churches that burned candles for up to nine hours at a time.
They found ten times as many damaging free radicals — molecules that can cause cancer — in the air inside the churches as they did in the air beside a motorway.
It is known that soot particles can penetrate the deepest parts of the lung and, as such, have the potential to aggravate respiratory illness.
Professor Hamidi says that some people who believe they have an allergy or irritation that causes wheezing may be reacting to the pollutants from candles they are burning at home.
Experts at the British Lung Foundation say that occasional use of candles is unlikely to cause problems, but that it is sensible to light them only in well-ventilated rooms and for short periods of time.
Meanwhile, an online survey carried out by Asthma UK last December found that scented candles were items that made a quarter of respondents’ asthma symptoms worse.
HOW TO BURN CANDLES SAFELY
If you can, opt for beeswax or soy-based candles, which have a relatively clean bill of health.
Non-scented candle produce less soot and air particles, so choose them for their ambiance.
Look for hard wax — avoid soft, gel wax which is often used because of its ability to hold colour and fragrance well, but is made from petroleum oil turned to a jelly.
Thin, braided wicks that seem to curl when they are lit are ideal — avoid thick wicks.
Tapered candles tend to be the best for your lungs.
With multi-wick candles, check that they burn evenly
Make sure the room is well-ventilated but not with a draft. Candles in a draft can produce up to 50 per cent more soot.
Make sure the candle has a low, even flame when it is burning.
Editor's note: This article has been edited for length.