Is Candle Burning Harmful to Your Health?

If you love the soft glow and comforting scent of a candle, you’re not alone. For many people, lighting one is a simple ritual for relaxation or ambiance. But as natural and “nontoxic” options fill store shelves, more people are wondering: Are conventional candles actually harmful to your health? And if so, are the “clean” ones really any better?

The Science Behind Candle Emissions

When a candle burns, it does more than melt wax and release scent; it sparks a small combustion process. In that process, the wax breaks down into a mix of gases and tiny particles that enter the air around you.

Some of those emissions are harmless, like carbon dioxide and water vapor. Still, others can include trace amounts of volatile organic compounds (VOCs)—a broad group of chemicals that easily evaporate at room temperature. VOCs are common in everyday life; they’re found in cleaning products, paints, furniture and cosmetics. However, when trapped indoors, high levels can irritate the eyes, nose or throat, particularly for individuals with asthma or allergies.

The good news is that for most people, lighting a candle occasionally in a well-ventilated room poses little to no risk. The not-so-good news is that poorly made candles, or frequent burning in small or enclosed spaces, can contribute to indoor air pollution over time.

Wax Matters: Paraffin vs. Natural Alternatives

Most mass-produced candles are made with paraffin wax, a petroleum byproduct that’s inexpensive and widely used. When burned, paraffin can emit more soot and VOCs compared to plant- or animal-based waxes.

In contrast, natural waxes such as soy, beeswax and coconut wax tend to burn cleaner and produce fewer emissions. However, no wax is entirely “emission-free.” Anything that burns releases at least some byproducts.

If you’re looking for a safer option:

• Choose candles labeled 100 percent soy or pure beeswax (not “blends,” which can still contain paraffin)
• Avoid candles with metal-core wicks--though lead has been banned in the U.S. since 2003, older or imported candles may still contain it
• Trim wicks to about ¼ inch before lighting to reduce smoke and soot

Are Scented Candles Worse?

Fragrance is one of the biggest factors in candle emissions. Many scented candles use synthetic fragrance oils that can release additional VOCs and phthalates-- compounds linked to headaches, allergic reactions and hormone disruption in some studies. The heat of a flame also can alter the chemistry of essential oils, meaning even “natural” scents may emit new byproducts as they burn.

If scent is a must, opt for candles labeled phthalate-free or made with pure essential oils, and burn them for short periods with good airflow.

Who Should Be Most Cautious

For most healthy adults, moderate candle use is unlikely to cause harm. But certain people are more sensitive to poor air quality, including:

• Those with asthma, COPD or allergies
• People with cancer, heart disease or compromised immune systems
• Older adults

If you don’t fall into one of these categories, and if you’re mindful about ingredients, burn time and ventilation, you can still enjoy that familiar, calming glow without worrying about what’s in the air.