Are Candles Bad for You? Health Risks, Benefits, and Safe Use Explained
Wax selection and proper ventilation brighten space without compromising air quality.
Lighting candles is a beloved tradition bringing comfort, warmth, and fragrance to homes. But concerns about the health effects of burning candles—especially scented and paraffin-based ones—have grown in recent years. This article examines what science says about candle emissions, potential health risks, environmental impact, and how you can use candles more safely in your living space.
What Happens When You Burn a Candle?
When a candle burns, it undergoes combustion, releasing not only light and scent but also various substances into the surrounding air. The type and amount of these emissions vary depending on the candle’s wax composition, the wick material, and added fragrances or dyes.
- Common candle wax types: Paraffin, beeswax, soy, coconut, palm.
- Main emissions: Particulate matter (tiny solid or liquid particles), volatile organic compounds (VOCs), polycyclic aromatic hydrocarbons (PAHs), and occasionally, trace metals or soot.
- Fragrances: Added to most scented candles, fragrances may contain dozens of different chemicals, some of which may be potentially harmful when airborne.
For most people, burning a candle or two in a well-ventilated room is not expected to cause major health concerns, but under certain conditions or with certain types of candles, risks can increase.
What Are the Health Risks of Candle Use?
A significant body of research has examined candle emissions and their potential health impacts, but the evidence is more nuanced than headlines may suggest.
1. Indoor Air Pollution and Candle Emissions
Candle burning releases fine particles and gases that may contribute to indoor air pollution, similar to other household sources like cooking or smoking. Major emissions include:
- Particulate matter (PM2.5 and ultrafine particles): Can be inhaled deep into the lungs, potentially causing respiratory irritation.
- VOCs: Substances like benzene, toluene, naphthalene, and formaldehyde are sometimes detected; some may have carcinogenic or irritant properties at high concentrations.
- PAHs (Polycyclic Aromatic Hydrocarbons): Generated mainly from incomplete combustion, implicated in several health conditions with chronic high exposure.
- Soot: More likely when candles are burned for long periods, in drafts, or when the wick is too long or made of certain materials.
2. Scented Candles and Fragrance Risks
Scented candles are a common source of indoor fragrances, but can also emit more VOCs. According to studies, the composition and amount of emissions vary greatly depending on the raw materials and manufacturing process.
- Some studies find VOCs from scented candles, including potentially carcinogenic benzene and naphthalene, are present, but typically at levels below regulatory thresholds for toxicity under normal use.
- However, emissions can accumulate in poorly ventilated environments and tend to be higher in paraffin wax candles, especially if burned for prolonged periods.
- Cheaper, paraffin-based candles often produce more soot and higher levels of irritating chemicals.
3. Who Is Most at Risk?
Most people using candles occasionally in ventilated spaces may not experience noticeable adverse effects. However, certain groups may be more sensitive or at increased risk:
- Individuals with asthma, allergies, or other respiratory conditions.
- Children and the elderly, who may be more vulnerable to air pollution.
- People spending long periods in rooms with burning candles or using them in small or poorly ventilated spaces.
Common Symptoms Linked to Candle Exposure
Clinical and survey research indicates a range of minor to more disruptive symptoms are reported by regular scented candle users, especially with frequent or prolonged burning:
- Headaches (most frequently reported)
- Respiratory symptoms: Shortness of breath, coughing, wheezing, chest tightness
- Allergic reactions: Sneezing, stuffy nose, watery eyes, throat or mucous membrane irritation
- Dizziness or vertigo (some individuals)
- In rare cases, skin irritation (contact dermatitis) or exacerbation of asthma attacks
One survey found around a quarter of scented candle users reported health problems: 15% had headaches, 9% shortness of breath, and nearly 8% experienced coughing. The likelihood of symptoms increased with burning duration (especially over 60 minutes per session).
Are Candles Carcinogenic?
Concerns have been raised about potentially carcinogenic emissions from some candles, particularly those made from paraffin wax containing synthetic fragrances and colorants. Formaldehyde, benzene, toluene, and PAHs are chemicals linked to cancer, and can be produced during burning, especially under incomplete combustion.
| Candle Type | Main Source | Relative Emissions | Health Risk (Typical Home Use) |
|---|---|---|---|
| Paraffin | Petroleum byproduct | Higher VOCs, soot, PAHs | Potentially higher, especially in poorly ventilated rooms |
| Soy/Coconut/Palm | Plant-based | Lower VOCs and soot overall | Lower, but still emits particulates and VOCs |
| Beeswax | Natural wax | Lowest emissions; some evidence of purifying effect | Lowest, generally considered safer |
While normal household burning of candles does not appear to consistently exceed regulatory standards for carcinogenic exposure, cumulative effects—with heavy or chronic use and lack of ventilation—are a legitimate reason for caution.
What Does Scientific Research Tell Us?
The results of large and small studies examining candle use and health are mixed, and often depend on:
- The frequency and duration of candle use
- The types of candles tested (paraffin vs. soy vs. beeswax, scented vs. unscented, etc.)
- Ventilation in the space
- The sensitivity or health status of individuals
Some notable highlights include:
- One large cohort study in Denmark found no statistically significant association between candle use (even more than 4 times a week) and hospital admissions for cardiovascular or respiratory events such as asthma, COPD, or myocardial infarction. However, more refined exposure studies are still warranted.
- Other studies have linked higher ultra-fine particle (UFP) counts (from burning candles) to lower lung function and elevated inflammatory biomarkers in indoor settings, especially with frequent use or poor ventilation.
- In susceptible individuals, especially those with pre-existing sensitivities, candles—particularly scented or paraffin-based—can trigger or exacerbate symptoms including headaches, dizziness, respiratory discomfort, or asthma.
Environmental Impact of Candle Burning
The environmental consequences of candle use vary by material:
- Paraffin wax is a byproduct of petroleum refining. Burning paraffin candles releases additional greenhouse gases and can contribute to local air quality issues.
- Soy, coconut, and palm waxes are derived from renewable resources, but their farming—especially palm—can contribute to deforestation and loss of wildlife habitat.
- Beeswax is considered the most sustainable and clean-burning mainstream option, though supply is limited.
Myth vs. Science: The Benefits of Burning Candles
Candles are commonly marketed for their calming effects, ability to ease stress, and promote relaxation or wellness through aromatherapy. However, rigorous studies cast doubt on these claims:
- A 2021 study found that burning scented candles did not lower indicators of stress (such as serum corticosterone) in humans, and in fact, exposure correlated with increases in certain pro-inflammatory biomarkers suggesting possible detriment rather than benefit.
- The psychological benefits of candles may relate more to ambience and traditional associations than biochemically-driven relaxation.
How to Burn Candles Safely: Evidence-Based Tips
If you enjoy burning candles, there are several ways to minimize risks:
- Choose higher-quality candles made from natural waxes like soy or beeswax, with cotton wicks, and avoid those with excessive synthetic dyes or fragrances.
- Burn candles in well-ventilated rooms. Open windows or ensure there is air circulation.
- Trim the wick to 1/4 inch before lighting. Long or mushrooming wicks can increase soot production.
- Limit burning sessions to under 1 hour when possible.
- Avoid burning multiple candles simultaneously or in very small, enclosed spaces.
- Never leave burning candles unattended, and keep away from pets, children, or anything flammable.
- If you or anyone in your household has asthma, chemical sensitivities, or respiratory disease, avoid regular candle burning or use only unscented, clean-burning types.
Candle Alternatives for Allergies and Respiratory Health
- Use LED flameless candles for ambience and safety—especially in bedrooms or around pets and children.
- Essential oil diffusers (with proper ventilation) can provide fragrance without combustion-related pollution, though essential oils can still trigger allergies in sensitive individuals.
- Increase natural light and fresh flowers to brighten your home without emissions.
Frequently Asked Questions About Candle Safety
Q: Is it bad to light a candle every day?
A: Occasional use in a well-ventilated area is considered safe for most healthy adults. Avoid long-term, daily burning—especially of scented or paraffin wax candles—in small or poorly ventilated rooms, as regular use increases inhalation of fine particles and VOCs.
Q: Are soy or beeswax candles really better for your health?
A: Soy and beeswax candles typically emit fewer toxic VOCs and less soot than paraffin candles. Beeswax is the cleanest-burning option. Both are preferred for indoor air quality, but should still be burned with proper ventilation and moderation.
Q: Can candles cause cancer?
A: Some candle emissions—like benzene or formaldehyde from paraffin—are known carcinogens, but typical household use is unlikely to reach levels that significantly increase cancer risk. Cumulative or chronic exposure in poorly ventilated spaces does increase theoretical risk. Choosing higher quality candles and using them sparingly minimizes any potential risk.
Q: Why do candles cause headaches or dizziness for some people?
A: Scented candles emit VOCs and fine particles, which may irritate airways or affect sensitive individuals’ nervous systems. These chemicals can trigger headaches, dizziness, or allergic reactions, particularly in individuals with migraine or chemical sensitivities.
Q: Are natural air fresheners like essential oils safer than candles?
A: Essential oil diffusers do not produce combustion byproducts, so they may be safer for air quality, but the oils themselves can still cause allergies or irritation in some people. Always use in moderation and with good ventilation.
Summary: Should You Burn Candles at Home?
For most healthy individuals, an occasional candle—especially natural wax, unscented, and in a ventilated space—shouldn’t cause major health issues. Individuals with respiratory, allergy, or migraine tendencies or those burning candles very frequently should exercise more caution. Being aware of the candle ingredients, burning conditions, and ventilation is the best way to balance enjoyment with safety and wellbeing.
References
- https://pmc.ncbi.nlm.nih.gov/articles/PMC9546142/
- https://pubs.acs.org/doi/10.1021/acs.est.3c07574
- https://www.mdlinx.com/article/this-household-item-may-spark-joy-but-it-has-serious-health-harms/3DSWAVcBfOeh6fte0Kx7Cb
- https://pmc.ncbi.nlm.nih.gov/articles/PMC10783381/
- https://www.nature.com/articles/s41598-025-95010-0
- https://health.clevelandclinic.org/are-candles-bad-for-you
- https://monell.org/the-new-york-times-are-scented-candles-harmful-to-your-health/
- https://www.healthline.com/health/are-candles-bad-for-you
Similar Articles
Read full bio of medha deb
