Those pretty candles might be a hazard to your health. (Photo: Corbis Images)
Your favorite candles and room sprays may be leaving behind toxic levels of air pollution.
A recent episode of the BBC series Trust me, I’m a Doctor featured a small experiment where a team of chemistry and environmental experts measured the levels of chemicals in six homes in the United Kingdom.
And here’s what they discovered: The ingredient limonene — which is commonly used to give citrus candles, air fresheners, plug-ins and cleaning products their scent, and is also used as a flavoring in foods — changes from safe to unsafe once it mixes with naturally-occurring ozone in the air. More specifically, every two molecules of limonene produced one molecule of formaldehyde, a cancer-causing chemical which has also been linked to skin irritation and respiratory conditions.
Interestingly enough, the researchers then supplied the test homes with four houseplants—English Ivy, Spider plant, Dragon Tree and Golden Pothos—for a four-week period since previous research has indicated that certain plants may have chemical-absorbing properties. Air samples were taken after the four weeks.
On the one hand, the levels of limonene rose, most likely because the homeowners had candles burning with their doors and windows shut tight due to the cold weather. However, formaldehyde levels decreased, suggesting that plants may have played a role.
“We were very surprised at how high the concentrations were of fragrance chemicals in some modern and energy efficient homes,” lead study investigator Alastair Lewis, professor at the National Center for Atmospheric Science at the University of York, tells Yahoo Health. “These compounds have always been present, but increased domestic usage coupled to reduced air exchange appears to be leading to elevated concentrations.”
Furthermore, he explains that these concentrations “are sufficiently high that the oxidation products such as formaldehyde begin to become significant.”
While it may be safer to opt for fragrance-free cleaning products, there’s no need to toss out your favorite jarred candles and scented votives.
“Fragrances have been used for thousands of years and we’re certainly not suggesting that they should be avoided,” stresses Lewis. “But in modern homes and offices where air exchange is limited, we’d recommend moderating usage and ensure regular exchanges of air to reduce the build up of secondary chemicals, such as formaldehyde.”
So the next time you’re setting the mood with tea lights, you may want to crack open a window, as well.