Harmful scented candles: understanding the real risks
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In Switzerland, scented candles are among the favorite items to create a warm atmosphere at home. However, a survey by the magazine 60 millions de consommateurs, published in September 2025, revealed that indoor fragrances release pollutants that can harm health. This raises an essential question: are scented candles harmful to your health, or does the danger mainly depend on their composition and use? To better understand this issue, we invite you to explore our in-depth analysis of the impact of scented candles on health.
Far from alarmist shortcuts, the reality is nuanced. Not all candles are the same. The type of wax, the nature of the wick, and the quality of the fragrance directly determine the emission profile of each candle. This article offers you a comprehensive insight, based on the most recent scientific data, to help you make informed choices and continue enjoying your candles with peace of mind.
What candle combustion releases into your indoor air
Any flame produces residues during combustion. This phenomenon is inevitable, whether it is a fireplace fire or a simple candle. The central question is therefore not whether a candle emits substances, but which ones and in what quantity.
When a scented candle burns, it mainly releases carbon dioxide (CO₂), carbon monoxide (CO), volatile organic compounds (VOCs), and fine particles. Among the most concerning VOCs are benzene, formaldehyde, and toluene. These substances are recognized as irritants or potentially carcinogenic with high exposure.
The EBENE reference study, conducted by ADEME in 2017, identified scented candles and incense as "sometimes significant sources of gaseous and particulate pollutants in indoor air." This study remains the scientific reference foundation on the subject in France and Switzerland today.
It is, however, essential to nuance these results. Emission levels vary considerably depending on the candle's composition. An industrial paraffin candle with synthetic fragrance does not emit the same substances as a handmade vegetable wax candle with carefully selected fragrances.
Paraffin, vegetable wax, and wick: the components that make all the difference
The composition of a candle is the primary factor determining your respiratory health. Three elements deserve special attention before any purchase.
Wax: the foundation of clean combustion
Paraffin, derived from petroleum, remains the most used wax in the candle industry. Its production cost is low. However, its combustion can release polycyclic aromatic hydrocarbons (PAHs), classified as probable carcinogens by the International Agency for Research on Cancer.
Vegetable waxes (soy, coconut, rapeseed) are a much healthier alternative. Their combustion is generally slower and cleaner, with significantly reduced VOC levels. To learn more about this topic, check out our guide explaining why choosing a vegetable wax candle is a concrete step for your well-being.
The wick: a detail that matters
Metal-core wicks (lead, zinc) can release traces of heavy metals during combustion. In the United States, lead-containing wicks have been banned since 2003. Natural cotton or linen, without metal reinforcement, ensure regular combustion free of metal particles.
Fragrance: natural does not always mean harmless
Cheap synthetic perfumes often contain phthalates, synthetic musks, and benzene derivatives. These substances are recognized as endocrine disruptors or allergens. However, even burned essential oils are not without criticism; their combustion can also release formaldehyde and benzene in low concentrations.
The key lies in the quality of the fragrances and their dosage. Grasse perfumes, crafted according to centuries-old expertise, allow for precise control of olfactory compositions and minimize unwanted emissions.
The latest scientific data on candle toxicity
In 2025, a study published in the journal Frontiers in Public Health specifically evaluated VOCs emitted by scented candles. The researchers confirmed that the type of wax directly influences the toxicological profile of emissions. The study also highlighted markers of oxidative stress and lung inflammation in subjects exposed for prolonged periods.
At the same time, the French government portal Notre Environnement reminded in November 2025 that incense and candles “are already known to emit pollutants (fine particles, formaldehyde, benzene).” This reminder is based on a joint study by the Scientific and Technical Building Center (CSTB), Aix-Marseille University, and INERIS.
These findings converge. The danger does not come from the candle itself, but from its composition and conditions of use. A handmade candle made of 100% vegetable wax, with a cotton wick and quality fragrances, has a much more favorable emission profile than an industrial paraffin-based product.
Concrete health risks: between alarmism and reality
Should you give up all your candles? The answer is clearly no. Risks exist, but they depend on three main factors: frequency of use, product quality, and room ventilation.
The most commonly documented side effects include:
- Irritation of the respiratory tract (coughing, sneezing, runny nose)
- Headaches and dry eyes
- Worsening of asthma in sensitive individuals
- Allergic skin or respiratory reactions
Certain groups of people need to be extra cautious. Pregnant women, infants, the elderly, and individuals suffering from asthma or respiratory allergies are particularly vulnerable. For these groups, it’s not about giving up the pleasure of candles, but about taking extra precautions and choosing only clean-burning products.
To precisely identify risky products, we recommend consulting our complete file on toxic scented candles.
Comparison table: industrial candle versus handmade vegetable wax candle
| Criterion | Industrial candle (paraffin) | Cap-Nature handmade candle (vegetable wax) |
|---|---|---|
| Type of wax | Paraffin (petroleum derivative) | 100% vegetable wax |
| Wick | Cotton with possible metal core | Natural cotton without metal |
| Fragrance | Synthetic, opaque composition | Grasse perfumes, controlled composition |
| VOC emissions | High (benzene, toluene) | Significantly reduced |
| Ingredient transparency | Low | High (Swiss artisanal manufacturing) |
| Burning time | Fast and uneven | Slow and even |
This table illustrates the considerable gap between the two product categories. The choice of wax, wick, and fragrance is not a marketing detail; it directly affects the quality of the air you breathe.
Seven essential steps to use your candles with complete peace of mind
The good news is that a few simple precautions are enough to significantly reduce risks. Here are the recommendations that are widely agreed upon by health authorities.
- Ventilate the room for at least ten minutes after each use. ADEME particularly emphasizes this essential step.
- Limit burning time to two or three consecutive hours maximum.
- Trim the wick to about five millimeters before each lighting to reduce soot production.
- Avoid multiple combustion sources (candle and incense simultaneously) in a confined space.
- Choose a vegetable wax and a wick without metal to limit harmful emissions.
- Keep the candle away from drafts that cause uneven burning and more smoke.
- Always extinguish the candle when you leave the room or before going to bed.
To go further with best practices, find our detailed advice for properly using your scented candle.
How to choose a truly healthy candle in Switzerland
With the increasing number of offers on the Swiss market, it is not always easy to distinguish a quality product from a well-packaged industrial item. Here are the criteria to systematically examine.
First, check the type of wax. A mention of "vegetable wax" should be clearly indicated, ideally with the precise source (soy, coconut, rapeseed). Any candle simply labeled "wax" without further details likely contains paraffin.
Secondly, examine the composition of the wick. Natural cotton without a metal core is the safest standard. Thirdly, pay attention to the origin and transparency of the fragrances. A manufacturer who clearly displays the source of their scents shows a real commitment to consumer health.
Finally, prioritize artisanal and local production. Short supply chains allow better control of every production step, from raw material selection to product finishing.
Olfactory pleasure without compromising your well-being
Giving up scented candles is neither necessary nor desirable. The real challenge is to make informed choices by understanding what each component means for your indoor air quality. The most recent scientific studies all confirm the same finding: it is the candle’s composition that determines its harmfulness profile of scented candles, much more than simply lighting it.
In Switzerland, growing awareness of indoor air quality is leading more and more consumers to turn to artisanal products with transparent and controlled composition. A 100% vegetable wax, a natural cotton wick, and carefully crafted Grasse fragrances form the best combination to balance pleasure and safety.
This is precisely the philosophy we uphold: clean combustion, traceable ingredients, and artisanal craftsmanship shaped by hand in our workshop in French-speaking Switzerland. Discover now our ecological candles and treat yourself to a ritual as healthy as it is refined.
Frequently Asked Questions
Are scented candles dangerous for daily use?
Moderate and occasional use does not pose a major risk for a healthy person. The danger mainly comes from intensive use of paraffin-based candles and synthetic fragrances in poorly ventilated spaces. By choosing a vegetable wax candle with a cotton wick, like those handmade by Cap-Nature, you minimize harmful emissions.
What is the difference between a paraffin candle and a vegetable wax candle?
Paraffin is a petroleum derivative whose combustion emits more VOCs (benzene, toluene) and fine particles. Vegetable wax (soy, coconut, rapeseed) burns more slowly, produces less soot, and releases significantly fewer problematic substances.
Should you air the room after using a scented candle?
Yes, systematically. ADEME recommends airing the room for at least ten minutes after extinguishing the candle. This simple action helps renew the air and remove any combustion residues.