Are Scented Candles Destroying Your Indoor Air Quality?

August 20, 2019
Scented Candles
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People have been using scented candles for years trying to mask unpleasant odours in their homes. They’re a go-to when trying to relax and unwind after a long days work.

Though they may seem safe, regular scented candles are actually a major source of indoor pollution, and destroy air quality. They put off chemicals that are considered just as dangerous as second-hand smoke.

According to Anne Steinemann, an environmental pollutants expert, certain candles may emit numerous types of potentially hazardous chemicals, like benzene and toluene (1). They can disrupt the nervous system, cause damage to the brain and lungs, as well as cause developmental problems.

“I have heard from numerous people who have asthma that they can’t even go into a store if the store sells scented candles, even if they aren’t being burned,” Steinemann said. “They emit so much fragrance that they can trigger asthma attacks and even migraines.”

Studies On Scented Candles

Many studies on scented candles have been performed, so I’ll outline a few below.

One study conducted by the Department of Civil and Environmental Engineering at the Hanyang University examined whether the amount of toxins varied with fragrance, based on six different scents (2). Scented candles, lit or not, contain volatile organic compounds (VOCs), which can be incredibly toxic when inhaled.

They found that when a candle was lit, formaldehyde was in highest concentration out of any VOC emitted. As we know, formaldehyde is listed as a hazardous compound, and its vapours are considered highly toxic (3).

The scents that emitted the highest concentrations of formaldehyde were as follows (ppb = parts per billion):

  • Strawberry: 2098 ppb
  • Clean Cotton: 1022 ppb
  • Plain: 925 ppb

The Centres for Disease Control and Prevention (CDC) states that, “acute and chronic health effects of formaldehyde vary depending on the individual. The typical threshold for development of acute symptoms due to inhaled formaldehyde is 800 ppb; however, sensitive individuals have reported symptoms at formaldehyde levels around 100 ppb (4).”

Another study conducted by researchers at South Carolina State University (1) tested both petroleum-based paraffin wax candles and vegetable-based candles that were non-scented, non-pigmented and free of dyes.

The vegetable-based candles didn’t produce any harmful pollutants, however the paraffin candles “released unwanted chemicals into the air…for a person who lights a candle every day for years or just uses them frequently, inhalation of these dangerous pollutants drifting in the air could contribute to the development of health risks like cancer, common allergies and even asthma,” professor Ruhollah Massoudi said.

You get the same kind of results with studies looking at air fresheners, like Febreze. Your best bet is to just stay away from synthetic anything.


The CDC has warnings and recommendations for formaldehyde exposure in the home. Home owners are urged to stop exposure, especially when there are individuals with asthma, elders, or young children present in the household.

Short-term exposure to formaldehyde released from candles results in the following symptoms:

  • Watery and burning eyes
  • Burning in throat and nose
  • Nausea and/or vomiting
  • Wheezing and/or coughing
  • Burning skin and/or irritation

Long-term exposure to chemicals found in candles can also cause cancer within the nasal passages, and even worse, leukaemia (5). Constantly breathing in chemicals found in candles can also lead to cognitive impairment, and certain types of dementia.

Source: Live Love Fruit