A new research warns that using scented candles may be potentially lethal and may lead to the development of cancer. The study conducted by the researchers from the University of York claim that an important ingredient in scented candles, when mixed with air, emits dangerous levels of the toxic substance formaldehyde.

Lead researcher Alastair Lewis, a professor from the National Center for Atmospheric Science at the University of York, assessed six modern houses in five days. Lewis measured volatile organic compounds (VOCs) in the air of these houses and found out that the most common chemical was limonene, the ingredient that manufacturers use to give candles their lemony aroma.

Limonene has also been used to give a citrus scent to air fresheners and cleaning products. Moreover, the chemical is also considered safe by the food industry to flavor food.





However, limonene reacts with other gases when released into the air, leading to its conversion into formaldehyde. Apparently, every two molecules of limonene produces one molecule of formaldehyde.

The findings show that the limonene in scented candles was 100 times higher than previously thought. Many homes do not have the proper ventilation to help lessen the high concentration of formaldehyde given off, which can have bad long-term consequences on one’s health.

Formaldehyde is commonly known to be used in embalming and by the industries like steel and chemical manufacturing. Apart from being toxic and corrosive, experts believe that it can also cause cancer. Additionally, formaldehyde may also cause nosebleeds, sore throats, coughs and stinging eyes upon contact.

However, Lewis noted that certain houseplants are good at reducing the amount of formaldehyde in the air. The professor suggested homeowners to have English ivy, geraniums, lavender and many ferns in their homes which are excellent in absorbing formaldehyde, making the air safer.