What’s really in your candle?

A candle looks simple: wax, a wick, and fragrance. The label does not always tell the whole story.

There is also a basic fact worth saying plainly. Every candle is a small open flame. Burning one changes the air around it. How much depends on the formula, the wick, the stability of the flame, the size of the room, ventilation, and how long it burns.

That does not make every conventional candle dangerous. In a controlled study of 24 scented and unscented candles, most modeled indoor concentrations were below the health-based guidance values used by the researchers. It does mean that “natural,” “clean,” and “non-toxic” are not substitutes for a clear ingredient list or careful candle use.

Here is what is worth looking for—and what the evidence actually says.

1. Paraffin wax

Paraffin is a petroleum-derived wax made from a mixture of hydrocarbons. When a candle burns, its fuel is heated, vaporized, and combusted. That process can produce ultrafine particles, soot, and volatile compounds. Those emissions are not unique to paraffin; candles made from plant waxes and beeswax also create combustion products.

The most accurate conclusion is not that every paraffin candle is harmful. Research shows that emissions vary widely from one candle to another, and wax type by itself does not reliably tell you what will be released into a room. Fragrance, wick composition, flame behavior, and airflow matter too.

What you may notice: A smoky or unstable burn can leave black residue and may bother the eyes, nose, or throat, especially in a small or poorly ventilated space.

What to look for: A maker that names the wax blend instead of asking you to accept a vague “premium wax” description.

2. Undisclosed fragrance blends

“Fragrance” can describe a complex mixture. That word alone does not prove a candle contains something harmful, and “synthetic” does not automatically mean unsafe. The concern is transparency and individual sensitivity.

Both natural and synthetic scent materials release volatile organic compounds. Some people—particularly those with asthma, allergies, migraines, or fragrance sensitivity—may experience headaches, coughing, wheezing, dizziness, nausea, or irritation of the eyes, nose, and throat around fragranced products. Other people notice no symptoms at all.

What to look for: A brand that tells you how the candle is scented, keeps the scent level considered rather than overpowering, and offers a truly unscented choice.

3. Phthalates

Some phthalates are used as solvents or fixatives in fragrance mixtures, helping scent last longer. They are not present in every scented candle, so it is inaccurate to treat “fragrance” and “phthalates” as interchangeable.

A 2025 study found diethyl phthalate in emissions from the small group of candles and incense products it tested. The researchers also said more work is needed to understand the effects of long-term inhalation at real-world levels. In other words: there is a reason to ask the question, but not a reason to turn uncertainty into a frightening promise.

What to look for: An explicit phthalate-free statement from the candle maker.

4. Dyes and unnecessary additives

Colorants and other additives can change how a candle burns, but there is not enough evidence to assign one universal health effect to every dyed candle. A colored candle is not automatically unsafe.

We still think a shorter formula is a better starting point. If an ingredient adds color but does not improve the candle, leaving it out is a reasonable choice.

What to look for: Dye-free wax and a maker willing to explain what is—and is not—in the candle.

5. Lead-cored wicks

This one is not a wellness trend. It is a real, well-documented hazard.

Lead-cored candle wicks could release lead into indoor air and onto household surfaces. Lead builds up in the body, and children are especially vulnerable to its effects on the developing nervous system. The U.S. Consumer Product Safety Commission banned the manufacture, import, and sale of candles with lead-cored wicks above the legal limit in 2003.

Current candles sold legally in the United States should comply with that rule. Extra caution still makes sense with very old candles or products from an uncertain source.

What to look for: A clearly identified cotton, paper, or wood wick and an explicit lead-free statement.

6. Soot from an unstable flame

Soot is not an ingredient, but it belongs in this conversation because the way a candle burns can matter as much as what is in it.

Laboratory work shows that a flickering, stressed flame can produce sharp increases in soot and fine-particle emissions. Long wicks, moving air, and debris in the wax can all disturb the flame.

What to look for: Clear care instructions. Keep the candle away from drafts, follow the maker’s wick-trimming guidance, and extinguish it if the flame repeatedly smokes or leaves visible soot.

Natural does not mean reaction-free

Essential oils are natural, but they still contain volatile scent molecules. A person who reacts to fragrance may also react to an essential-oil candle. For a scent-sensitive home, unscented is the clearest choice.

If any candle causes a headache, coughing, wheezing, dizziness, or irritation, put it out and bring fresh air into the room. People with a respiratory condition should follow the guidance of their healthcare professional.

Our ingredient standard

Glow Guardian is poured from soy 55%, coconut 35%, and beeswax 10%, with three lead-free cotton wicks. Our scented candles use essential oils, and 07 Tranquility is unscented.

No paraffin. No phthalates. No dyes. No synthetic fragrance.

Those choices do not make an open flame emission-free. They make the formula shorter, the materials easier to understand, and the decision in front of you more informed. That is what ingredient transparency should do.

A more considered way to burn

• Choose a candle with a clearly named wax, wick, and scent source.
• Use an unscented candle if fragrance bothers you.
• Bring fresh air into the room while burning any candle.
• Keep the flame away from drafts and follow the candle’s care instructions.
• Stop using a candle that smokes heavily or causes symptoms.

You do not need fear to read a label carefully. You only need a maker willing to show you what is there.

Explore the collection → · See our ingredients →

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Sources

• Measurement and evaluation of gaseous and particulate emissions from burning scented and unscented candles, Environment International, 2021.
• Emissions of soot, PAHs, ultrafine particles, NOx, and other health-relevant compounds from stressed burning of candles in indoor air, Indoor Air, 2021.
• Sources and Composition of Indoor Particulate Matter, National Academies of Sciences, Engineering, and Medicine, 2024.
• Fragrances and indoor air, American Lung Association, updated 2026.
• Incense and Candle Burning: A Major Source of Phthalate Exposure in Indoor Environments, Indoor Air, 2025.
• CPSC bans candles with lead-cored wicks, U.S. Consumer Product Safety Commission, 2003.