Candles: Health Benefits, Risks, and Safety Tips

Medically Reviewed by Dan Brennan, MD on September 16, 2021
4 min read

Candles are popular for relaxation, mood, ambiance, and decoration. There’s a lot of debate about whether candles are good or bad for your health. Here’s what the research says.

Mood and scent are closely linked. This connection happens because odor molecules in fragrance bind to proteins along your nasal passage and create electrical signals. These signals can interact with a part of your brain called the limbic brain and affect your emotions, thoughts, and memory.

Molecules are also small enough to cross the blood-brain barrier and interact with your nervous system. Some scents can help lower blood pressure and heart rate and change brain activity.

You might turn to candles after a long day or when you’re feeling stressed. Burning a candle can help lower stress and promote relaxation. These benefits come more from the scent than the candle itself.

Lots of candles contain essential oils. These are natural compounds from plants that have medicinal benefits. Some cultures have used essential oils for physical, mental, and spiritual healing. Today, they are often used for relaxation and stress management.

Some essential oils are known to promote relaxation and sleep and lower anxiety. These include:

One of the concerns is that burning candles releases chemicals into the air that can make you sick. These concerns are often linked to paraffin wax and synthetic fragrance chemicals because they come from petrochemicals.

While studies show that burning candles does release toxic chemicals, it’s not clear that these chemicals harm your health.

A 2009 study said that burning paraffin wax releases gases and volatile organic chemicals like toluene and benzene, which are known to cause cancer. Burning candles also releases particulate matter like soot into the air. Breathing in large amounts of soot and volatile organic compounds (VOCs) can damage your DNA and lead to lung problems.

Another study says there’s a possible link between burning candles in poorly ventilated areas and bladder cancer. This study suggests that chemicals called phthalates are the problem.

There are some disagreements with these concerns, though. The first point is that data from some of this research wasn’t published, prompting organizations to question whether it is reliable.

The second disagreement is that particulate matter and VOCs from candles are too small to be a concern. A 2014 study tested candle emissions and found that candles don’t release enough chemicals to be carcinogenic under normal use.

Chemicals from candles are known allergy and asthma triggers. People with these conditions have inflamed airways. They are more sensitive to chemical irritation, which can lead to flare-ups. Fragrance is a common asthma trigger, but the paraffin wax might also be a problem.

Candles can cause allergy and asthma symptoms such as:

Smells are a known migraine or headache trigger for many people. About 95% of migraine patients say that sensitivity to smell either triggers or worsens a migraine or headache. This is called osmophobia. Common smells include car exhaust, cigarette smoke, and fragrance.

Scented candles can cause headaches and migraines for some people. Because the problem is often fragrance and not necessarily candles, unscented or natural candles may be okay to use.

In general, burning candles properly in your home is not likely to be toxic or harmful to your health. Candles are safe even though they might trigger allergies, asthma, or migraines. There are some ways to make candles even safer for your indoor air

Proper ventilation. The problem with candle emissions is not necessarily the emission levels but poor ventilation. Only burn candles in a well-ventilated room. Open a window while it’s burning, but keep the candle out of the draft.

Burn natural candles. Paraffin candles release different chemicals. Switch to beeswax, soy, or coconut oil-based candles. Check the label to make sure it’s 100% natural wax and not mixed with paraffin.

Avoid scented candles. If fragrance irritates you, go for unscented, natural wax candles. If you enjoy a scent, choose candles with natural essential oils instead of fragrance chemical oils.

Blow it out. Unattended candles are a common cause of household fires. Never leave a candle unattended. Make sure to blow it out before you leave the room or fall asleep.

Candles can add a lovely scent and ambiance that helps you relax after a stressful day. Candles are safe, but if you think you’re allergic, stop using them and talk to your doctor about your health.