Are Candles Bad for You? What Science Says

Published April 20, 2021
woman igniting candle

Are candles bad for you? The answer is often debatable and shrouded in tales of harmful candle emissions, denials by the candle industry, and numerous studies reveal that candle emissions are safe. When you explore the various answers to the question if your candles are bad for you, the best ones come from scientific studies. The researchers use proven tools and formulas to test the emissions from various types of candle waxes, as well as scented vs unscented candles.

Types of Candle Wax Emissions

You can examine the various properties of candle waxes to determine which might be best for you. There are several major waxes used in candles. These include beeswax, paraffin, soy, gel, and various waxes and wax blends.


According to Beeswax Candles, the beeswax is nontoxic and offers a clean burn. If you have allergies, Beeswax Candles states the wax is safe for you to use. In fact, beeswax candles are believed to have beneficial properties, such as:

  • Producing negative ions that are believed to be responsible for boosting the oxygen flow to your brain
  • Acting as a mood enhancer, much like the function of serotonin in the brain

Paraffin Wax

Some candlemakers believe paraffin has been given a bad rap. In fact, the USDA (United States Department of Agriculture) approved refined paraffin wax as a non-toxic product. Not all paraffins are equal, some produce a sooty smoke when extinguished and create an unpleasant smell.

Soy Wax

Soy wax candles are clean burning. They don't produce the type of smoke that a paraffin candle does. Many people sensitive to candle emissions and smoke opt for soy candles.


Gel wax candles are made of mineral oil and polymer resign. The emissions are deemed safe for consumer use. There have been reports of gel candles exploding. It would be more accurate to say that the containers of the gel candles exploded from overheating. Gel candles burn longer and hotter than paraffin and other candles, and often the containers used are not resistant to high temperatures and the containers crack or explode under the built-up heat.

Colorants for Candles

A colorant allows candle makers to focus on specific colors for the candle. The formulas for colorants are matched with the type of candle wax. Some colorants are natural and popular for beeswax candles and are safe to use with no harmful emissions.

Colorful candles

Dyes for Candle Coloring

Candle dyes come in powder and liquid forms. The dyes used in candle making aren't absorbed in the wicks enough to clog the wicks and create poor burn performance. However, dye colors can fade. The dye is safe to use for candle making with no harmful emissions.

Pigments for Colored Candles

The pigments in candles don't dissolve or bleed. This property means the candle color won't fade. However, pigments aren't added to candles since the pigment will clog the wick and prevent the candle from burning. Pigments are only safely used as an outside coating for a candle. You can see a pigment candle when the candle color doesn't run through the candle. If you scratch the surface of the candle, you'll find a white candle underneath the outer coating.

Candle Scents

The candle scents are either essential oils or a synthetic fragrance. The candle fragrance standard is set by International Fragrance Association (IFRA) to ensure the scents used in the candle industry are non-toxic.

Harmful Candle Emissions Myths Debunked

Are candles toxic? The National Candle Association (trade association for US candle manufacturers and suppliers) published an article, Four Candle Myths Debunked, in an effort to correct what it termed as inaccuracies about candles. The association cites popular beliefs about the harmful health threats that burning candles pose to consumers and debunks them. These myths include wicks containing lead, harmful candle soot, unscented candles safer than scented ones, and candle wax differences.

Harmful Candle Emissions Report Challenged by NCA

In 2009, South Carolina State University (SCSU) issued a press release that long-term exposure to candle emissions could be harmful. The researchers tested paraffin and soy candles that didn't contain any scents, dyes, or pigmentations. They stated that every day use for years or frequent use could present health risks, such as asthma, allergies, and even cancer. The paper can be read on the USDA website.

Two Candle Associations Challenge SCSU Study

The National Candle Association (NCA) responded with criticism of the SCSU study and challenged the researchers. According to the NCA statement, they never received any response.

ECA Rebukes SCSU Study

The ECA (European Candle Association) also issued a statement refuting the SCSU study and referenced a 2007 internationally funded study conducted on emissions from candles and human health. The study concluded there were no concerns about harmful health emissions or air-quality from burning all types of candles.

2014 Study: Emissions Aren't Harmful

A 2014 study on possible harmful health effects from burning scent candles was published on ScienceDirect. The researchers concluded that under normal conditions, scented candles don't pose any health risks.

Young woman in a shop, smelling a scented candle

2017 Study: Lung Inflammation in Mice

In 2017, a study published by the National Library of Medicine examined lung inflammation and genotoxicity in the lungs of mice. The mice were exposed to a burning candle. The goal of the study was to compare the pulmonary effects of candlelight combustion particles and diesel exhaust particles. The researchers concluded, "pulmonary exposure to particles from burning candles is associated with inflammation and cytotoxicity in the lungs."

2018 Belgium Study: Candles Pose No Health Risk

In a 2018 published Belgium study on the health risks for burning scented candles. The group first established a mean burning time via a phone survey for a scented candle, which was no more than one hour.

One Hour Exposure Not a Health Risk

The analysis revealed emissions of formaldehyde, acrolein, and a smaller amount of PM (particulate matter). The team concluded that short term exposure to burning scented candles within the mean burning time of one hour is harmless and doesn't pose a health risk.

Denmark Study: Not Harmful Under Normal Exposure

A 2018 study conducted by the Ministry of Environment and Food of Denmark EPA Agency concluded that the candles tested emitted certain VOCs, but the levels were so low that they weren't considered harmful under normal exposure.

Candle Emissions Don't Threaten Health

The majority of candle emission studies are in agreement about candle emissions and your health. These studies find that while there are certain pollutant emissions, they are so small as not to pose a health threat. However, if you have certain physical ailments, especially asthma or allergies to scented products, you need to be cautious when buying and using candles.

Reduce Soot and Smoke to Minimize Pollutants

You can easily reduce soot and smoke from candle use and eliminate/reduce any pollutants. You can follow a few good candle practices. These include:

  • Keep the wick trimmed to around 1/4" long to ensure an even burn.
  • Snuff out the candle, instead of blowing it out to avoid candle smoke.
  • Eliminate drafts or move your candle so it isn't flickering and fluttering from air current changes.
  • Don't inhale candle smoke. Extinguishing the candle with a snuffer, in another room, or outside.
  • Read candle labels for any potential ingredients you may be allergic to.
  • Don't burn candles 24/7.

Are Candles Bad for You?

According to the bulk of scientific studies, candles aren't bad for you. You should always consider your personal health issues when burning candles and limit the burn time accordingly.

Are Candles Bad for You? What Science Says