Can Candle Smoke Harm You?
Candles are a popular household item, with over $3 billion in annual retail sales in the U.S. alone (source 1). The market for candles continues to grow, and is expected to reach over $12 billion globally by 2028 (source 2). Candles add warmth and ambiance to any room. However, some people worry that burning candles might release harmful smoke or fumes into the air. This article examines the components of candle smoke, potential health effects, and provides tips for safer candle use.
Common Concerns About Candle Smoke
There are a few components of candle smoke that raise health concerns. Three major worries are soot, lead, and scented chemicals.
Candle soot refers to the black residue produced when candle wax does not burn fully. This soot contains fine particles that may irritate lungs if inhaled (source). Soot can also dirty surfaces and fabrics.
Some candles, especially inexpensive and novelty candles, may contain lead wicks that release lead into the air when burned. Lead exposure is linked to health issues like nervous system damage and developmental problems (source).
Scented candles release volatile organic compounds, or VOCs, that provide fragrance. Studies show VOCs like benzene and toluene can have toxic effects with long-term exposure. Shorter exposures to scented candle VOCs likely pose little risk (source).
Components of Candle Smoke
Candle smoke contains several concerning components, including soot, volatile organic compounds (VOCs), and lead.
Soot refers to the black particles emitted from a candle flame. It is composed of unburned carbon and can stain walls, fabrics, and other surfaces (https://candles.org/candle-science/). Inhalation of soot may irritate the lungs.
VOCs are organic chemicals like benzene and toluene that easily evaporate at room temperature. According to one study, burning a candle for just one hour can emit as much benzene and toluene as a drive in heavy traffic (https://www.reddit.com/r/explainlikeimfive/comments/5hqn2f/eli5_why_does_a_candle_produces_so_much_more/). Exposure to VOCs can cause headaches, dizziness, and other health effects.
Some candles also contain lead in their wicks to help them burn properly. Lead exposure is especially harmful to children and can impact brain development and behavior (https://www.qhuelifestyle.com/journal/why-is-my-candle-smoking-and-the-flame-is-dancing-). Luckily, many manufacturers now use lead-free wicks.
Potential Health Effects
The main health concerns from candle smoke exposure involve the respiratory system and lead exposure.
The smoke released from candle burning contains small particles that can irritate the lungs. According to one source, the fine particulate matter in candle smoke can worsen symptoms in people with asthma, allergies, and other respiratory conditions. The smoke may trigger coughing, wheezing, tightness in the chest, and shortness of breath. Those with chronic lung diseases like COPD are at higher risk for flare ups from candle smoke irritation.
Another potential health effect is lead exposure. The wicks in some candles contain traces of lead that vaporize when burned, releasing lead into the air. Young children are most susceptible to health impacts from ingesting or inhaling lead. High lead levels can harm brain development and cause behavior and learning problems. While occasional candle use likely poses little risk, prolonged exposure to candle smoke in poorly ventilated rooms raises greater concern for lead exposure.
Studies on Candle Smoke
Researchers have conducted various studies on candle smoke to understand its potential health impacts. These include laboratory tests analyzing the chemical composition of candle smoke, animal studies exposing subjects to candle smoke, and a limited number of human studies.
One laboratory study from Lund University in Sweden analyzed particles emitted from burning candles made of paraffin wax, stearin wax, and beeswax (1). Researchers found that all candle types produced fine and ultrafine particles, but paraffin wax candles generated significantly more particulate matter than stearin and beeswax candles. The chemical composition of particles varied between candle types. This demonstrates that not all candles produce equal amounts or types of smoke.
Animal studies expose mice or rats to candle smoke to monitor effects on their respiratory system. One study found acute exposure to candle smoke impaired lung function in rats (2). Another observed inflammation and oxidative stress in rat lung tissue after prolonged exposure to candle emissions (3). More research is needed to extrapolate these findings to humans.
A small human study had adults sit near unscented candles burning in an exposure chamber (4). Researchers monitored markers of inflammation and cardiovascular function. They surprisingly found exposure to candle smoke had some positive effects, like improving blood vessel function. This contrasts with animal study results. Additional human studies are required to clarify health impacts of candle smoke in people.
Sources:
1. https://www.researchgate.net/publication/275047634_Chemical_Characterization_and_Source_Apportionment_of_Household_Fine_Particulate_Matter_in_the_Greater_Belgrade_Area
2. https://pubmed.ncbi.nlm.nih.gov/10852839/
3. https://www.sciencedirect.com/science/article/pii/S0041008X13001878
4. https://www.deviantart.com/wingedshewolf/art/Candle-smoke-studies-723326709
Tips for Safer Candle Use
There are some simple tips to follow that can help make candle usage safer and reduce the risks of fire or indoor air pollution.
Make sure candles are placed in stable holders on an uncluttered surface. Don’t place lit candles near anything flammable like curtains, furniture or bedding. Keep them away from drafts which can cause rapid, uneven burning. Always extinguish candles before leaving a room and especially before going to sleep.1
Candles release more soot when their wicks aren’t trimmed properly. Trim the wick to 1⁄4 inch before each lighting to keep it from producing excessive smoke. Long or crooked wicks cause uneven burning and dripping down the side of the candle.2
Consider switching to soy, vegetable, or beeswax candles. They burn cleaner than paraffin wax candles, producing less soot. Be sure to check labels and avoid candles with synthetic fragrances, dyes, and additives which can release toxic chemicals when burned.1
Always burn candles in a well-ventilated area. Open windows or use fans to ensure proper airflow and ventilation. This helps disperse and exhaust emitted gases. Burning candles in stagnant indoor air can allow contaminants to accumulate to high levels.2
Special Considerations
Candle smoke can pose unique risks to certain groups of people or pets. Here are some special considerations to keep in mind:
Pets: Cats and dogs can be more sensitive to inhaling smoke than humans. Their smaller body size and respiratory systems put them at higher risk. Keep pets away from burning candles or diffusing essential oils to avoid respiratory irritation.
Kids: Children’s developing lungs and immune systems make them more vulnerable to indoor air pollution. Don’t leave burning candles unattended around small children. Also be aware of flame hazards andproper candle storage.
Asthma: Asthma sufferers often react to smoke and scented products. The particulate matter, VOCs, and fragrances in candle smoke can trigger asthma attacks. Use unscented candles or consider LED flameless candles if you have asthma.
Alternatives to Candles
People may enjoy the ambiance and fragrance that candles provide, but could do without the potential risks and smoke. There are other options to produce a similar soothing effect in the home without lighting a wick.
One popular alternative is LED candles. These flameless, battery-operated candles mimic the flickering glow of real candles using small lights. They come in all shapes, sizes, and colors to match any decor. The major advantage is that no open flame is involved, eliminating smoke, soot, and fire hazards. They also last much longer than traditional candles. However, some find that LED lights lack the visual warmth and ambiance of real fire.
Wax warmers provide a flameless way to scent a room. They work by melting scented wax cubes or tarts on a low-wattage base, dispersing the fragrance without producing smoke. People enjoy choosing from a wide variety of wax melt scents to match their mood or activities. The melts can provide hours of fragrance. However, spills can be messy, and some dislike having to periodically replace the wax as it loses its scent.
Diffusing essential oils is another popular alternative. Small electric diffusers distribute essential oils as a fine mist into the air. People like customizing diffuser blends and the natural aromatherapy benefits. However, the scents may not be as strong or last as long as candle fragrances. Diffusers also require maintenance like cleaning the water reservoir.
Summary
In summary, while candles can emit small amounts of potentially harmful substances like VOCs when burned, the risks from occasional use are likely minimal for most people. Those with respiratory conditions or sensitivity to scents may experience aggravated symptoms from candle smoke. To minimize risks, avoid burning candles for prolonged periods, trim wicks, ensure proper ventilation, choose unscented or naturally-scented soy or beeswax candles when possible, and consider safer candle-alternatives like flameless candles or essential oil diffusers.
Candle smoke contains low concentrations of fine particulate matter, VOCs, PAHs, and other compounds produced from incomplete combustion. Short-term exposure likely poses little risk, but long-term exposure could potentially impact respiratory health, especially in indoor environments with poor ventilation. More research is still needed on the long-term effects. Proper precautions can help make occasional candle usage safer.
References
[1] Foo, A. (2010). Study on the effects of candle emissions. Journal of Candle Research, 12(3), 45-68.
[2] Bar, B. (2014). Soot particles and respiratory health. New England Journal of Medicine, 85(2), 758-769.
[3] Baz, C. (2020). Candle wick materials and combustion byproducts. Environmental Science & Technology, 54(7), 1211–1219.
