Safety of using candles with essential oils

Can we use essential oil candles safely?

Yes, but only if, after reviewing the scientific studies that analyze this practice, you really feel safe. You can still enjoy the emotional benefits of burning candles if they are not scented.

If you decide to use candles with essential oils, I also encourage you to review the Precautions section at the end of the article. There are some recommendations that should be kept in mind.

That said, let's see what the studies say! Links to them are at the end of the article.

What do the studies say about burning scented and unscented candles?

In the most recent study, from 2021, emissions from 24 types of candles (combinations of different waxes and wicks) were studied. In general, all emissions independent of the wax and wick used had emissions significantly below the accepted safe levels. The fragrances used were a mixture of substances including essential oils of Lavandin, Lavender, Lime, Orange, Peppermint, Peppermint, Patchouli, Vetiver, and Jasmine Absolute. Due to the heating, specific volatile substances (limonene, benzaldehyde, etc.) and other types of particles were observed in the air near the candle. Due to the very large number of substances present in the formulation of the fragrances added to the candles, it was not possible to determine the exact cause of the emissions. However, even in the case of scented candles, the particulate emissions were well below the permitted limits.

A 2014 study sought to analyze whether cumulative particulate emissions from candle burning and other indoor sources could have a negative impact on human health. It concluded that, under normal conditions, burning scented candles does not pose a health risk.

A 2010 study investigated whether the particulate emissions from burning citronella candles react with ozone in the air to form dangerous compounds. The results were not very conclusive, but recommendations were made to avoid burning candles outside during the day (when ozone is high).

A 2007 study funded by the European Candle Association examined each major type of wax for 300 toxic chemicals. Researchers found that the level of chemicals released by each type of candle was far below the amount that would cause health problems in humans. At this time, there is no conclusive evidence that burning candle wax is harmful to health.

Another study in 2008 determined that other activities such as burning food, using the stove, vacuuming and lighting candles or other plant mixtures had small and statistically insignificant effects on indoor particle concentrations.

Studies in 1997, 2006 and 2008 attempted to estimate actual human exposure to candle emissions and to characterize the associated risks to human health. All three investigators concluded that, on the basis of their investigations, candle emissions are unlikely to have long-term effects on human health. They emphasized that short-term exposures may trigger or aggravate certain symptoms in sensitive individuals.

Other concerns

Another issue that has also emerged as a concern is the possibility of oxidation of oils. The burning temperature of the candle has been measured and is over 800°C (1470°F) at the wick and flame, 40-50°C (104-122°F) the body of the candle, and ~60°C (140°F) at the surface where there is melted wax. Indeed, the presence of heat, light, and air could lead to oxidation of the oils in scented candles. However, a necessary factor is missing and that is time, which is generally much too short for oxidation of oils. The recommendation is that candles should not be kept burning for more than 4 hours, followed by 2 hours cooling. Even when a candle is lit more than once, the time of exposure of essential oils to factors that can lead to oxidation is short. Studies show that the amount of essential oils that actually burn is very small under normal conditions and emissions are well below the permissible limits.

Phy Phy Phytes are another concern. The ban on lead-containing phthalates many years ago has simplified this issue somewhat. However, it is always advisable to check their source and quality. Cotton is also a highly pesticized crop. To minimize risks, opt for organic cotton wicks.

Both in studies and online there is a lot of talk about VOC emissions that could be harmful. VOCs (volatile organic compounds) are not always harmful. On the contrary! Essential oils for example are volatile organic compounds with beneficial effects. Pine forests are also rich in VOCs with positive health effects.

Conclusions

Just like any activity we do (using a knife, crossing a street...), burning candles, scented or unscented, can also have risks. At the same time, half of the cities in Europe are above the WHO limit for some of the same parameters measured for candle burning. The concentration of PM2.5 in Romanian air is currently 3.2 times higher than the WHO's annual air quality guideline value (according to https://www.iqair.com/romania)

There are, however, a number of precautions which, if taken, can minimize or completely eliminate these potential risks.

In the Tisserand Institute's Safety in the Use of Essential Oils course, we were given an amusing but all the more memorable example. There is a difference between the possibility and the probability of something harming us, for example using a blade to shave a person or to shave a bear.

Always be safe!

If you have questions, please send us a message

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