Toxic aroma therapy

Hanyang: Professor Ki-Hyun Kim has conducted research regarding habits and life choices of people in relation to air pollution – electronic cigarettes and the use of scented candles to name a few – and his paper “Characterization of hazardous and odorous volatiles emitted from scented candles before lighting and when lit” was selected as paper of the week as it was published in Journal of Hazardous Material. The popularity of scented candles has grown as the use of candles expanded from lighting to indoor air freshener, aromatherapy and decor.
“With the growing demand for scented candles, the U.S. market for scented candles is estimated to be worth about 2 billion USD per year,” explains Kim in his paper. Not only in the States but also in Korea, the demands for scented candle are rapidly growing; take this past Teacher’s Day, for example, scented candles were among the most popular gifts.
The candles you lit to unwind and cure stress and insomnia, however, may potentially be hazardous to your health. “According to our study, toxic compounds like formaldehyde were emitted in large quantities from some scented candles before and when lit.” Among the various volatile organic compounds (VOCs), scented candles release are pleasant aromas and also toxic components. “These compounds identified include, but are not limited to, various aldehydes, hydrocarbons, and alcohols. A number of polycylic aromatic hydrocarbons (PAHs) identified as carcinogens were also observed,” explained Kim. He also added, “like many indoor activities facilitating the emissions of fine and ultrafine particulates, cotmbustion of scented candles can play a key role as a source of particulate matter as well as various gaseous pollutants.”

To identify the characteristics of VOCs from scented candles, Kim and his team conducted laboratory experiments using six candle types: clean cotton, floral, kiwi melon, strawberry, vanilla, and plain for reference. Then, they collected gaseous emission samples of scented candles from before and during combustion and analyzed them for VOCs and carbonyl compounds.
Kim compared the results of his research to two criteria to calculate the harmfulness of VOCs emitted from scented candles: the time weighted average values of VOCs by the American Conference of Governmental Industrial Hygienists (ACGIH) and the time weighted averaged values set by the Occupational Safety and Health Administration (OSHA). “Concentration of most compounds did not exceed the two types of guidelines values. However, the most significant exception was found from FA,” said Kim. “Long-term exposure in these environments is likely to increase the risk of developing serious disease including even cancer in humans.”
“Of course, further investigation and research is needed to make an accurate conclusion regarding the potential risks associated with scented candles and indoor pollution. It is especially important as more and more people are incorporating them in their daily lives for various purposes,” concluded Kim.