Are Candles Bad for You?

Candles are a surefire way to cozy up your evening, but are you breathing in toxins while you Netflix next to one for hours? Here's the scoop.

Can you even imagine a self-care day, spa appointment, bubble bath, or chill night in without a luxurious, scented candle? Even if you're not into aromatherapy or essential oils — there's something so zen and beautifully indulgent about lighting a candle in your favorite scent.

This simple but delightful wellness practice is probably getting a little more attention now that everyone's more clued into respiratory health right now (thanks, COVID!). So it's worth asking: When it comes to candles, do you need to worry about what you're inhaling?

Experts and studies have varied takes, but the consensus is that you can probably keep your favorite Diptyque burning. Read on for specifics.

Can Candles Be Toxic?

Candles seem to be a safe choice, but with a few considerations. "There's conflicting evidence in the literature addressing the question of toxicity in candles," says Mary Brummitt, N.P., One Medical primary care provider based in Seattle.

One study published in Regulatory Pharmacology and Toxicology in 2014 evaluated the volatile organic compounds (VOCs), semivolatile organic compounds (SVOCs), and particulate emissions from scented candles. (VOCs are emitted as gases from certain solids or liquids and include a variety of chemicals, some of which may have short- and long-term adverse health effects, according to the Environmental Protection Agency.) This study found that "under normal conditions of use, scented candles do not pose a known health risk to the consumer."

Meanwhile, "other studies have shown that candles do emit chemicals into the atmosphere, but at levels too small to be a legitimate health risk, especially if you're not burning them daily," says Habib Sadeghi, D.O., founder of integrative medicine center Be Hive of Healing.

That brings up an important distinction. "Toxicity risk increases when candles are burned in closed confined spaces for multiple days, over prolonged periods of time," says Megen McBride, N.D., natural medicine doctor at Four Moons Spa in Encinitas, CA. "However when used occasionally with adequate ventilation, risks are significantly lowered, so cracking a window can be very beneficial."

However, McBride still believes candles have the potential to be "very toxic" depending on the materials used to make them. Specifically, "lower-quality waxes, and synthetic, inorganic oils." She pointed to studies and a survey that looked at scented products in general, which assert that scented products may cause adverse reactions, particularly in people who are asthmatic or have chemical or fragrance sensitivities.

"It's very important to look at all labels of any items you purchase for food, drink — and, yes, even those you burn or diffuse into your breathable air such as candles and essential oils," says McBride. "Not all manufacturers are required to list all ingredients on their labels, so it's important to buy from trusted sources."

Karin Grow, a San Diego-based artist and candlemaker who has made, sold, and distributed wholesale candles for nearly two decades, says she lives a healthy, organic life, and feels her candles fit in line with that lifestyle. "I've made candles for more than 17 years and used all different types of waxes, always looking for healthier alternatives," says Grow. "With all the talk about chemicals and pollutants on websites and social media," she — like many people — was concerned and dove into as much research as possible to ensure she wasn't creating a product that would harm her customers (or herself!).

So, unfortunately, the answer to the question "are candles bad for you?" isn't so simple. There is potential for toxicity, but the line is fuzzy. You would likely have to be burning a lot of candles, for many consecutive hours, in a poorly ventilated room to experience negative effects. And when it comes to the type of candle you're burning, various factors — including the wick, wax, scent, and your own sensitivities — all come into play.

Watch the Wick, Smoke, and Soot

Wick toxicity has historically been the biggest candle-related concern, but that should be a thing of the past. "The most agreed-upon conclusion is that candles with lead or other metal-containing wicks can be toxic," says Brummit. Wicks that contained lead could potentially cause lead poisoning if the fumes were inhaled, explains Dr. Sadeghi. The good news: "Most manufacturers stopped using leaded wicks in the 1970s, and they were officially banned by the U.S. Consumer Product Safety Commission in 2003, along with imported candles containing lead," he says. "So that's no longer a concern."

That said, anything that's combustible (meaning, can catch fire) can release carbon and soot via smoke, says Grow. Soot is the black substance you see around the wick or on the surface of the wax after a candle has been burned. "Scented candles tend to burn with more soot because the compounds added for scent change the carbon-to-hydrogen ratio in the candle, which affects the way it burns," explains Brummitt. "And soot particles, which can be inhaled, may cause inflammation in different parts of the respiratory system including the bronchioles [the little 'branches' in the lung] and even the smallest parts of the lungs, the alveoli."

The amount of soot coming off your candle likely isn't dangerous, but you still want to avoid directly inhaling smoke for that reason. "There are some candles — such as soy — that smoke less, but the only smokeless flame is a blue flame (think, the flames from propane)," explains Grow.

What About the Type of Wax?

"Many synthetic fragrances and paraffin candle waxes are known to give off VOCs, especially when burned," says Brummitt. "This includes compounds that are known carcinogens, such as formaldehyde and benzene."

But, are you even getting close to a harmful amount of VOCs with a Jo Malone Peony & Blush Suede burning on your coffee table? Perhaps not.

"The debated question is if the amount of VOCs you're exposed to when burning a candle indoors reaches a level harmful to human health," she says. "This question needs more good research to be fully answered."

Most candles are made with paraffin wax, which is petroleum-based since it's a byproduct of making gasoline, says Dr. Sadeghi. "The other problem with paraffin wax candles is that they release soot, which contains chemicals similar to those found in diesel exhaust," says Dr. Sadeghi. "Whereas vegetable-based and natural waxes such as palm wax, coconut wax, beeswax, and soy wax are better choices that produce far less soot. The cleanest choice is probably beeswax, which people have been burning for thousands of years, although it's likely the most expensive."

Among the "ways to avoid some of the air pollutants would be to buy candles made from natural waxes instead of paraffin waxes," agrees Brummit. "This could be candles made with beeswax, soy wax, or others. Often these waxes will be 'fragrance-free' but still have their own naturally pleasant scent."

McBride echoes this sentiment: "100 percent beeswax or organic vegetable-based waxes are significantly healthier alternatives." Not every candle will be labeled with the kind of wax inside; you may have to do some digging into the brand you're buying or burning to see what wax they use.

And even if your candle is emitting questionable substances into the air, "according to the [scientific] findings, the amount of VOCs emitted [by any candle] isn't enough to cause harm in humans," explains Dr. Sadeghi. "It's important to remember that people are exposed to VOCs and particulate matter every day from other sources including car exhaust, especially if they live in a large city or near a highway. While it's never good to be inhaling chemicals, they can hardly be avoided in the modern world, so we must keep everything in perspective and focus on quantity and frequency of exposure."

McBride points out that you need to watch your respiratory health in general when it comes to these compounds. "The air sacs within your lungs are very thin and allow chemicals breathed in to quickly enter your body," she says. "Air pollutants can also enter your body via your skin, nose, eyes, and mucus membranes in your mouth and throat. Indoor air quality is of utmost importance not just to those who struggle with allergies such as asthma, itchy throats, and headaches, but also for the possible long-term effects that VOCs have, which may include respiratory disease, heart disease, and cancer."

Synthetic vs. Natural Fragrances

The role of fragrance in candle safety is debated, too. For starters, neither natural nor synthetic fragrances are ideal if you're inherently allergic or sensitive — and this isn't exclusive to candles, says Brummitt. "Synthetic or natural fragrances are both sensory stimuli and are known to cause headaches in sensitive individuals," she says. "In fact, fragrances are considered one of the most common triggers for migraines."

"Synthetic fragrances and essential oils both contain allergens, so you could have reactions to both — just because essential oils are plant-based, doesn't always mean they're safe!" agrees Grow. "For some, essential oils can be very toxic (specifically for pregnant women, and they're also super toxic to pets). Always do your research first and save yourself a trip to the ER or vet."

Different types of fragrances have different effects on a candle — known as the "scent throw", explains Grown. "Scent throw is used to describe how well the scent circulates throughout the room," she says, noting that essential oils — the only real "natural" way to fragrance a candle — don't have a great throw. "I love my essential oils, but they're not really suitable for burning in wax. The heat degrades the oil and there is little scent thrown while burning, so they actually smell stronger when the candle is unlit. In addition, they don't bind well with wax, so most candle makers either have to add a ton [of fragrance] which is expensive, or need to use stabilizers in the candle." That's why there aren't many naturally-fragranced candles out there — and if you do find one, it might not really smell like anything once you light it.

That's why Grow uses cosmetic-grade synthetic fragrances in her candles. "Synthetic fragrances go through way more testing [compared to natural fragrance] — especially cosmetic-grade oils [aka fragrance], which has cleaner ingredients," says Grow.

Even though the availability and performance of natural fragrances are limited, not everyone is on board with them. Dr. Sadeghi, specifically, is still in favor of naturally-scented candles. "Evidence also shows that scented candles release VOCs and particulate matter into the air, including formaldehyde and benzene,"— chemicals that are known to cause cancer, according to the Centers for Disease Control and Prevention (CDC). "This is because the artificial fragrance is derived from petrochemicals [chemicals derived from petroleum]," he says. "Always look for candles with natural scents, such as those scented with essential oils," says Sadeghi. "Forget about the candles with scents like banana split or cookie dough. Any product that contains the generic ingredient 'fragrance' includes phthalates," he says. (Phthalates are chemicals used to make plastic more flexible and which may have negative repercussions on human health, though the CDC admits the human health effects from exposure to low levels of phthalates are unknown.)

How to Safely Burn Candles

Okay, so maybe there's not enough VOC coming out of your favorite candle to warrant tossing it in the trash, but if you're erring on the side of caution, there are options for you. As all the experts pointed out, vegetable or beeswax candles are a safe bet, with non-metal wicks, in a well-ventilated area, in short doses throughout the week or month.

There are a ton of candles that meet those criteria. Heretic is notable for the transparency of their ingredient lists (take "This Smells Like My Orgasm," for instance). Boy Smells' trendy candles are made from a beeswax and coconut blend, and PF Candle Co, Homesick, and Herbivore all use soy wax. The Beeswax Co. has an arsenal of lightly honey-scented (naturally, with no added fragrance) 100 percent beeswax candles with cotton wicks, as do many Etsy shops. (Yay for supporting small businesses!)

No matter which type of candle you're burning, Grow offers these tips to help your candle burn longer, cleaner, and with less smoke exhaust and sooting:

  • Cut the wick to 1/8'' and only burn for a few hours at a time. If the wick gets too long, the flame is too big and burns hotter — causing a smoke trail and higher emissions of VOCs, soot, and other byproducts. Trimming the wick will help "reduce soot and thereby reduce unwanted air particulate matter," agrees McBride.
  • Burn in a well-ventilated room (but not drafty, or your candle will burn too fast and unevenly).
  • Use a snuffer to extinguish your candle, place the top back on it, or — better yet — take it outside to blow it out. This will keep the soot and smoke out of your house.
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