A New Report Suggests Candles Are Bad For Our Health – But How Worried Should We Be?

As someone who has cultivated a ‘candle cupboard’ (yes, that is an entire cabinet devoted to my bougiest bougees and no, I do not live in a mansion; far from it in fact), a recent report warning of the apparent health risks associated with burning candles cut deep. So much so that I almost didn’t read it as I knew that whatever the outcome, my love of wax would never wane and I would carry on burning regardless (perhaps just with slightly less abandon or when the kids are at school depending on how damning the report was).

Because for many of us, candles are part of our everyday rituals and a comfort few of us are willing to relinquish (the UK home fragrance market generated a revenue of almost £541 million in 2023 and is expected to reach over £950 million by 2030). There’s something about that gentle flickering glow that warms the very cockles of our souls and are a balm for HD screened-out eyes. They have the ability to create a calming, intimate atmosphere that speaks to our primordial selves (being able to create fire being what sets us apart from our hairy ape cousins). And don’t get me started on their miraculous ability to impart a kind filter to over-40s skin; Richard E. Grant did a recent house tour on Instagram where he confessed; 'My candle bill is very large – I burn a lot of candles because it’s the best lighting if you’re over the age of 35 – which I astonishingly am – candlelight is the most gorgeous thing.'

A mantra to live by methinks and I could go on. But back to this study (as I gently cradle Jo Malone’s Velvet Rose & Oud deluxe candle). The headline-grabbing report penned in The Conversation by Dr Asit Kumar Mishra, at the University College Cork and Dr Marie Coggins at the University of Galway was pegged on their studies into the impact of energy retrofits in Irish homes which found that activities such as burning candles, smoking and blocking wall vents can have a significant negative effect on indoor air quality. In fact, using scented candles when combined with closed windows and blocked wall vents can increase peak fine particle concentrations to 15 times the limits prescribed by the World Health Organization levels which they found can take a while to return to normal levels in unventilated rooms (flickering flames in particular increase emissions of black carbon).

So what is it about candles that make them a potential health hazard? According to Mishra and Coggins, burning candles or incense sticks ‘produces a complex mix of chemicals and particulate matter, including toxic gases like carbon monoxide, sulphur dioxide and oxides of nitrogen as well as being a major source of formaldehyde.’  So far so depressing. According to the duo even short-term exposure to candle smoke has been shown to reduce cognitive function and it’s the particulate matter which can cause both short-term health effects such as coughing and irritation to the eyes, nose and lungs as well as worsening some existing conditions such as asthma and increasing the risk of heart disease, lung cancer and chronic bronchitis (incense sticks produce around four times as much particulate matter as cigarettes and scented candles are likely to produce more fine particulate matter than non-scented candles). It’s something echoed by Head of health advice at Asthma + Lung UK. Erika Radford; “This is the time of year for winter candles and burning incense, but there is a general lack of awareness of their potential health harms. Candles and incense sticks emit particle matter (PM) and other pollutants when they're burned and there is evidence linking incense burning to lung disease, so high levels of exposure should be avoided.”

But for those who covet candles and wax lyrical about scented wax, all is not lost according to both Radford, Mishra and Coggins; 'If you love to use home fragrances, then there are ways to reduce your exposure to potentially harmful chemicals. For example, try to use home fragrance products in larger spaces, such as the living room, and open windows. Check that any vents have not been blocked in your home – especially in a room where you plan to use home fragrances. Finally, most of the smoke from candles is emitted when the flame is extinguished. To be on the safe side, always try to snuff out candles outdoors,' (aka the perfect excuse to buy Dior’s Candle Snuffer £34).

I’ll admit the news has made me re-evaluate burning several candles in my teeny, tiny (unventilated, window-free) bathroom, but the living room will remain a flaming ode to ouds and warming woody notes (a recent report branded wood burners Britain’s biggest source of dangerous air pollution and I reason I don’t have one of those). And for those who want to scent their homes sans candles? Here are the very best.

Shop: The Best Home Fragrances

Cassie Steer is acting health and beauty director at Grazia with over 25 years’ experience on women’s glossies.