Burning candles: Is there reason to worry about health

The basic raw material for the production of candles is wax, which, however, can come from various sources and thus fundamentally influence the technological properties of the candles and the degree of riskiness of their burning. The most widespread material is undoubtedly paraffin wax, which is typical for candles from a lower price category. You can meet it most often with tea candles, stick candles and cemetery candles. This colorless to white substance with a melting point of around 48–66 °C is obtained by crystallization of mineral oil, which is one of the  by-products of crude oil distillation. Although the origin of paraffin may seem scary, this substance has been used in healthcare for years, mainly due to its positive effect on moisturizing the skin and also through its use in thermotherapy (heat therapy). When used correctly, its application is completely safe, but several rules must be followed, such as not applying paraffin wraps to open wounds or, due to its flammability , keeping it away from open flames.

In addition to paraffin, candles can also be made from beeswax or vegetable wax. You can meet, for example, soy, palm or coconut. A higher purchase price is typical for these candles.

What exactly happens when you burn candles? 

To light a candle, you need a heat source, which is most often fire from a lighter or a match. As soon as you bring this heat source closer to the candle, a small amount of wax will melt around the wick. This liquid wax is then sucked into the wick and allows it to catch fire and continue burning. The temperature in the wick area reaches up to 1400 °C, making it the hottest point of the entire flame. If you are interested in this process in more detail, you can visit the National Candle Association website .

The high temperature further leads to the vaporization of the liquid wax into a mixture of gas and solid particles, which is further drawn into the flame. The smoke then consists of a mixture of carbon particles and other organic and inorganic substances  – their type and concentration depend on many factors, such as the type of wax, the content of dyes or fragrances in the candle, the length of the wick, the type of metal used for the wick plate, etc. The mixture of these substances is then released into the room during combustion.

What do they say about burning study candles? 

If the previous text scared you, and you are halfway to the trash can with all the candles in the house, read on. Although it is undeniable that particles are released into the air during burning, their amount is so low that the conclusions of the studies do not indicate a risk to human health. Even here, however, the degree of burning and the (un)suitability of the external conditions depends.

With good ventilation in the room and the normal intensity of candle burning, the concentration of substances released into the air did not reach such a level as to harm human health – neither with candles made of natural materials, nor with paraffin ones. However, a study from 2013 showed that in candles made from natural materials (here specifically palm wax), the concentration of some substances was up to half lower than in cheaper paraffin variants. So, if you are avid autumn “users” of candles, you can still minimize the very low risk of harm to your health by purchasing products from natural sources.

How about scented candles?

However, the situation is more difficult with candles containing dyes or fragrances. Even these added substances come into contact with the flame and fragments of these compounds are released into the air. According to the conclusions of the studies,  the concentration of substances released when burning scented candles and candles without perfume differed dramatically  – however, it should be noted that none of the product groups exceeded the threshold where the amount of these substances would have a negative effect on health.

In addition, not all scented essences are suitable for use in scented candles, and toxic or irritating substances may be released when they are burned. Whether these substances can really negatively affect human health depends mainly on the specific type of compound and also the concentration in which the original substance was used. Therefore, if you buy a scented candle from a manufacturer that guarantees the appropriate type and concentration of the scented ingredients used, it will be a safer choice than in the case of home production. Again, however, it is worth mentioning that no study has so far recorded a case where burning any candles in a normal amount would negatively affect human health.

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How to burn candles safely? 

As mentioned above, the risk of burning candles negatively affecting your health is very small. However, there are certain principles, following which you can take this activity to an even higher level of security. The National Candle Association recommends following these guidelines:

1. Trim the wick and remove any debris before lighting the candle: trimming the wick will extend the life of your candle and ensure that it burns at the optimum temperature. If the wick is too long, the base of the flame will be too far from the reservoir of liquid wax, and the burning will not proceed optimally. The recommended length of the wick is approx. 0.6 cm. By removing impurities, you will prevent the accidental ignition of other substances and the release of their fragments into the air.
2. Do not light candles in a draft: Although ventilation is desirable when burning candles, do not place them near open windows, fans, etc. Air flow can disturb the burning and cause the flame to flicker, which releases more smoke.
3. Do not burn the candle for more than 4 hours: these time limits are recommended due to the accumulation of carbon molecules at the top of the wick, which can cause a higher rate of their release into the air if they burn continuously for too long. If you want to light it again after a pause, wait at least 120 minutes.
4. After the end of burning the candle, ventilate it sufficiently: although it was mentioned above that the concentrations of substances released into the air during burning are not in sufficient concentration to negatively affect human health, they can accumulate with frequent use of candles. It is therefore important to ventilate sufficiently every time so that you do not unnecessarily expose yourself to these substances in a closed space.
5. Do not leave candles unattended and remove flammable materials from reach: a basic safety rule. The risk of fire is definitely a greater danger than the substances released during the burning of candles.

If you are still hesitating to choose a candle, from the point of view of safety, you can choose almost any. If you want to minimize the already very low health risks, go for a natural or beeswax candle without perfume. 

Can burning candles have any benefits? 

The flickering flame of a candle hides a certain poetic quality, especially in the dry autumn weather. If you follow the above-mentioned principles, you can enjoy a few minutes of relaxation with a candle and a cup of hot tea without worrying about health risks. On the contrary, this activity can also bring you certain benefits:

• Reducing stress: candles are an ideal addition to relaxation, meditation or reading books (of course with lighting that is optimal for reading). They will help you create a pleasant ” hygge ” atmosphere, relax and work on your mental health. Why is taking care of the mental side an indispensable component of overall health? You will find out in the article Psychohygiene: the path to mental health.
• Bedtime Ritual: Nowadays, people are often used to working or watching TV until just before going to bed. However, according to studies , blue light can disrupt the sleep cycle and thereby reduce the quality of rest you get during the night. So if you replace the monitor with a moment of candlelight silence before bed, this ritual can better prepare you for the sleep to come. Looking for more easy ways to improve your sleep routine? You can find them in the article 9 tips to improve sleep.
• Aromatherapy: If you want to treat yourself to aromatherapy, instead of scented candles, an aroma lamp would be a better choice, where the scented oils are diluted with water, and what’s more, they don’t come into direct contact with fire. Aromatherapy can help you better manage stress, symptoms of PMS, insomnia or perhaps reduce the degree of feeling chronic pain. For more information, see the article Aromatherapy: Fragrant treatments with many benefits .

What to take from it?

The safety of burning candles has been the source of much controversy in recent years, with more than one website warning of the near-life-threatening consequences of this popular activity. However, if you dig into quality scientific papers, none of them to date have proven that any candles harm human health. Although some substances are released into the air, their concentrations are too low to have a negative effect.

However, when using candles, it is advisable to follow several principles, such as regular ventilation or placing the candle itself out of drafts. If you are an ardent “burner” and this activity is part of your daily routine, you can minimize potential health risks by purchasing a high-quality vegetable or beeswax candle that is fragrance-free.