Are scented candles and cleaning products making you sick?

You want your visitors to enjoy your home, but a musty odour is off-putting. So you’ve got your vanilla candles, lavender soap and eucalyptus cleaners to create a clean and fresh vibe. But what if these beautiful-smelling products are giving your guests migraines, or asthma? And that’s just the immediate health impact.

According to a 2021 research review published in the Air Quality, Atmosphere & Health journal, around one in three adults have a reaction to perfumed products. So, if you invite, say, 10 people around for a barbecue, chances are that at least three could be affected. But they’re probably hesitant to blurt out that your inner sanctum gives them a migraine.

With these rates of impact, Melbourne researcher Professor Steinemann calls it an epidemic.

“Fragranced products are creating health problems across Australia. The effects can be immediate, severe and potentially disabling,” she says in a University of Melbourne statement. “But they can also be subtle, and people may not realise they’re being affected.”

Along with headaches, fragrance sensitivity commonly creates breathing problems, asthma attacks, skin reactions and runny noses. More worryingly, certain fragrance chemicals may increase the risk of cancer, or interfere with the way our hormones work. For example, some musks can trick the body by acting like oestrogen.

When we talk about home fragrances you might think of aerosols, or those diffuser reeds in bottles. But the culprits also lie in your soap, dishwashing liquid and the detergent you washed your cushions with. While these scents might be subtle to you, to those who are sensitive, they are anything but. As one sufferer, Vicci Gates, describes it: “I can’t tolerate the new laundry products … they leave a fog of gas around those wearing clothes washed in them. I cannot escape them. I can’t breathe.”

Since the arrival of the pandemic, we’ve been motivated to clean with these products even more often. Another study published this year analysed 26 pandemic products including scented hand sanitisers, soaps, cleaners and disinfectants. Altogether they produced 127 potentially hazardous volatile organic compounds or VOCs (called “volatile” because they easily evaporate and waft about). And only 4 per cent of the volatile compounds were listed anywhere for consumers to find.

An example of a common VOC is limonene. It’s the scent of oranges and happens to turn to formaldehyde when it reacts with the ozone in our air. Formaldehyde is a known human carcinogen.

Perhaps you’re thinking, “No worries, I’ll just choose the more natural products.” Then you’ll be interested to know researchers found no significant differences between “natural” and regular pandemic products. Similar studies from the same research team pulled apart essential oils, air fresheners, and fragranced cleaning products. Again, both regular and “natural” versions emitted countless potentially hazardous compounds, and few were disclosed to users.

Given these worries, why are the ingredients of fragrances not listed on labels to let us make informed choices? There are 26 fragrance allergens that a spokesperson for the International Fragrance Association (IFRA) says its members are committed to disclosing. However, manufacturers often write nothing more detailed than “fragrance” or “parfum” on the back of the bottle. (Have a look at home.) On average, there are 14 secret ingredients in a perfume.

Understandably, manufacturers want to protect their trade secrets. And anyway, the full list would be “very long, unintelligible and confusing to most consumers”, according to IFRA.

Dr Ian Musgrave, a University of Adelaide pharmacology researcher, agrees, saying: “Merely knowing that a fragrance contains carvacrol, beta-Damascenone or 1,8-cineole is not helpful in the absence of other information.”

Helpful information would include knowing how well the safety of those ingredients had been tested in humans. There are nearly 4000 available fragrance ingredients on IFRA’s “transparency list”. Some have been tested, and some are restricted in how they’re used. However, with such a long list, and human studies being tricky (who wants to sign up to make sure you don’t get cancer?), we don’t know how all the ingredients affect us.

What we do know is the way you’re exposed to a chemical determines how it affects you. For instance, fragrance in soap that washes off probably has less impact than fragrance in sanitiser left on your skin. Also important is how much you’re exposed to.

“Unless you are susceptible to migraine or asthma, the concentration of these chemicals in fragrances is well below any potentially toxic effect,” Dr Musgrave says.

If you’re not entirely reassured, or have fragrance-sensitive guests, must your home smell au naturel? Firstly, no need to cut back on cleaning – just choose fragrance-free products.

After cleaning, to create a welcoming aroma, Dr Musgrave says not to use air fresheners to cover up unpleasant smells coming from something dangerous to your health, like mould or cigarette smoke. “It would be better to ensure a good flow of fresh air rather than using fragranced products or, if not allergic to flowers, less concentrated sources such as potpourri or flowers.”

Similarly, IFRA encourages “good practices” like ventilating the room and following guidelines on the bottle. With an open window, you can let both unpleasant odours and many concerns about chemicals float away on the breeze.