Are scented candles bad for you?

Burning a scented candle is a popular way to create a pleasant ambiance at home. Scents such as lavender, jasmine, and sandalwood can be relaxing and invigorating. During the holidays, many people find the warm glow and aroma of pine, gingerbread, or cinnamon makes a room feel more festive.

Unfortunately, most mass-produced scented candles can have a negative impact on indoor air quality. From the wax to the wick to the fragrance itself, the average scented candle can release harmful chemicals into the air — even when unlit.

So while you and your family may enjoy the fragrance of scented candles in your home, they may be harmful to your health. Read on to learn why some candles are bad for you.

Paraffin wax

Are paraffin wax candles safe? In what way can wax be harmful?

According to a 2017 study in the International Journal of Tropical Disease and Health, paraffin candles emit pollutants that can threaten human health and shouldn’t be burned in enclosed areas (1).

Most candles are made from paraffin, a petroleum byproduct. To create paraffin wax candles, petroleum waste is chemically bleached, deodorized, and made into wax. When burned, paraffin wax can release toxic volatile organic compounds (VOCs) into the air, including known carcinogens like:

• alkenes
• acetone
• benzene
• toluene

These are the same chemicals found in diesel fuel emissions and are known to cause allergies, asthma attacks, and skin problems.

A 2005 study published by the University of South Florida showed that candles made of paraffin wax emit low levels of benzene even when they are not lit (2).

Is burning candles bad for you?

In addition to releasing toxic chemicals, burning paraffin wax produces soot composed of particulate matter such as, PM2.5 and ultrafine particles that can remain suspended in the air for hours. According to the University of South Florida study, ultrafine soot particles are similar to diesel exhaust in both their size and composition. They penetrate deeply into the lungs and are absorbed into the blood stream (3).

A 2000 study conducted by the U.S. Environmental Protection Agency showed that soot emissions from candles are significantly higher after wax breakthrough occurs and when a candle is smoldering (4).

Ultrafine particles are associated with severe health issues, including:

• allergies
• asthma
• COPD (5)
• respiratory tract infections
• heart attacks
• strokes
• cancer

So, are candles bad for your health? Not all candles produce the same amount of air pollutants. A 2002 study published in the Journal of the American Oil Chemists’ Society found that soy wax, much like beeswax candles, burned at a significantly lower rate and resulted in less soot than paraffin candles (6).

Chemical fragrances

Another problem with scented candles is that the chemicals they use to create a pleasing aroma are generally far from wholesome.

Most scented candles use synthetic fragrances and dyes that give off dangerous VOCs even at room temperature. Commonly emitted VOCs related to the scent in candles include (7):

• formaldehyde
• petroleum distillates
• limonene
• alcohol
• esters

These harmful chemicals can cause health problems, such as:

• headaches
• dizziness
• allergy symptoms
• asthma attacks
• respiratory tract infections
• cancer

Cored wicks

Many candles have cored wicks made from cotton that are wrapped around a metal support. The design helps keep the wick from falling over into the wax. This is especially useful for scented candles because the fragrance oils soften the wax and allow non-cored wicks to go limp.

Are candles toxic? If they have lead in them, possibly. Lead was once commonly used in cored candlewicks — especially in candles imported from overseas. However, after determining that these wicks could present a lead poisoning hazard to young children, the U.S. Consumer Product Safety Commission banned the manufacture and sale of all candles with lead-core wicks in 2003 (8). Zinc and tin have been used as a substitute since the ban.

However, all metal-core wicks release trace amounts of heavy metals into the air when they are burned. Wicks with zinc and tin cores can still release small amounts of lead particles (9,10).

Safer alternatives

To limit soot stains and poor air quality in your home, you should avoid or restrict the use of candles (11).

If you still crave the pleasant ambiance and aroma of scented candles, here are safer ways to scent the air:

• Use essential oils for fragrance. Essential oils can be placed in a diffuser or in bathwater to create a desired aroma.
• Simmer spices. Place spices such as cinnamon sticks, cloves, and nutmeg in a pot of water and let it simmer on the stove.
• Create potpourri. Dried items such as flowers, berries, fruit rinds, wood chips, and spices can be placed in bowls or fabric bags and placed around your home.

The takeaway

Lighting scented candles may seem like a relaxing way to enjoy your home. But burning scented candles releases VOC pollutants and worsens your home’s indoor air quality. Although fragrances from safer alternatives like essential oils can be pleasant, truly clean air smells like nothing at all.