Non-Toxic Home Fragrance: Candles, Air Fresheners & Scent Alternatives

More About Non Toxic Candles and Safe Incense

I assess scent safety by thinking about three parts:

• The scent itself: 100% organic essential oils vs. natural essential oils vs. natural-synthetic blend vs. all-synthetic fragrance

• What the scent is blended with (the substrate): 100% pure plant-based oil vs. water vs. synthetic resins vs. petroleum-based paraffin wax. And, whether there are any harmful dyes mixed in to make it colorful, but create unhealthy smoke.

• How it is dispersed into the air in your home (the throw method): combustion (fire) along a cotton wick vs. combustion of an incense stick made of synthetic resins vs. evaporation vs. ultrasonic particle diffusion

Separating it into three parts captures a more complete picture of a fragrance's impact on your health.

For example, a perfectly healthy, 100% organic essential oil may be blended with a petroleum-based wax and burned, releasing a slew of unhealthy chemicals and smoke particles (PM 2.5.) On the other hand, a natural, not organic, essential oil may be diffused in pure water, making it a healthier choice overall.

Non-Toxic Fragrances and Scents

Are there safe scents for home use?

Yes. The safest home scents use 100% organic essential oils dispersed through evaporation (like reed diffusers) or simple diffusion in water. This avoids combustion entirely and keeps you away from synthetic fragrances, which are associated with reproductive harm, asthma, and endocrine disruption. If you prefer candles, look for ones with 100% organic essential oils in beeswax or soy wax with cotton wicks.

What is the difference between Fragrance Free vs Unscented?

Fragrance free confirms no organic, natural, or synthetic scents whatsoever have been added. Unscented means that the product doesn't have a detectable scent, but it still may actually have fragrances added to it. Confusing right? Consider Secret's Unscented Deodorant— it has fragrance added, probably to mask the less-pleasant smells that naturally come from the other ingredients in it. The same goes for non-deodorant, “unscented” home products.

Why are non-organic essential oils less healthy than organic ones?

Non-organic plants are typically grown with pesticides and synthetic fertilizers. These chemicals can remain in the final essential oil or candle.

Are natural fragrances healthy?

No. Natural fragrance, aroma, parfum, luxury scenting, fragrance oil— these are all innocent-sounding words for the same thing: they're synthetic fragrances, made from chemicals, in a lab. The word "natural" isn't defined or regulated in personal care products and fragrance in the United States, so it can be mis-used to make the product seem healthier than it is. Unless a fragrance's ingredients are "100% essential oil," it is not truly natural.

How do I know if a fragrance is synthetic?

Unless it is labeled "100% essential oil," it is probably synthetic.

Why are synthetic fragrances toxic?

Synthetic fragrances are notoriously bad for your health. They are associated with reproductive harm, asthma, heart disease, neurotoxicity, and more. There are 3,600+ synthetic fragrance chemicals currently, and dozens can be combined into one candle. These chemicals are often phthalates, which are endocrine disruptors.

What is IFRA certification?

The International Fragrance Association (IFRA) created its own Research Institute for Fragrance Materials (RIFM). This sounds good, but it's entirely self-regulating. Its operations are opaque— they decide what chemicals are "safe" for use in fragrance (rather than requiring disclosure of ingredients, so consumers can make their own informed choice about whether its healthy enough for them or not.) Many of the IFRA-approved ingredients, like benzophenone, methyleugenol and styrene, are known carcinogens. When a company claims its scents are safe because they are IFRA-approved, it's just not true. However, because they do limit some of the most harmful chemicals, I still consider IFRA-certified fragrance slightly better than uncertified fragrance.

Non-Toxic Candles

What are non-toxic candles made of?

Non-toxic candles use 100% organic essential oils for scent, beeswax or 100% soy wax (not "soy blend"), undyed wax, and cotton or wood wicks. This combination avoids petroleum-based paraffin, synthetic fragrances, phthalates, and toxic dyes that release harmful chemicals when burned.

Why is burning a candle bad for you?

Combustion — AKA, burning candles, incense, palo santo, sage, etcetera — exposes you to smoke over minutes to hours, and is filled with fine particulate matter (PM 2.5), carbon monoxide, nitrogen dioxide, sulfur dioxide. Depending on whether or not the scent you're burning is organic or synthetic, it also releases other gasses, VOCs, and phthalates into the air. PM 2.5 is related to heart and lung disease, cancer, and is increasingly associated with developing dementia. It is the primary reason wildfire smoke and outdoor air quality warnings are issued, and is best kept to a minimum inside your house. If you do decide to burn scents indoors, choose 100% organic and plant based when you can, ventilate well, and consider doing it for special occasions only.

What makes a candle non toxic?

Home fragrances— like candles, incense, and diffused aromatherapy— can be thought of in three parts: what the scent itself is made from, what it is blended with, and how it is dispersed into the air in your home. For example, the most non toxic candle would have 100% organic essential oil for scent, blended with beeswax and undyed, and have a cotton wick for releasing scent into the room.

Why is paraffin wax in candles bad?

Usually called paraffin, standard candles are made with this. It is extracted from petroleum as a part of the oil refining process, mixed with solvents, distilled, and then further processed — making it softer or harder, or adding dyes to make it colorful. Burning petroleum, solvents, chemical additives, and dyes pollutes your indoor air and is associated with many health problems. Formaldehyde and aromatic hydrocarbons like toluene and benzopyrene may be released in large quantities from commonly available scented candles, especially the less expensive ones made from paraffin wax. Some candles are labeled "coconut wax blend" or "soy wax blend." When you see the word "blend," it is likely blended with paraffin.

What is a tallow candle?

Tallow is rendered animal fat, typically from beef or sheep. It's similar to lard, and is what candles were made with until modern chemistry allowed us to create paraffin. While it isn't vegan, and burning it will still produce smoke inside, it is safer than burning petroleum-based paraffin.

What dyes should I avoid in candles?

In general, candle waxes are still colored using toluene derivatives and benzidine-based dyes, which have been associated with urothelial cancer development. Look instead for undyed wax, natural dyed wax, and even better, for the list of ingredients the dyes come from (like madder root, which makes red or pink candles).

I like my unhealthy candles. What can I do to make my candles less toxic?

If you already have a candle, incense, or fragrance oil you like, and it isn't very healthy, there are a few things you can do to minimize harm:

• Use candles as decorative objects, and don't burn them. Or, burn them very infrequently or on special occasions only. I know this won't work for everyone, but it is what I do— I burn my Christmas-scented incense cones once a year, and enjoy most of my fun-shaped and perfectly-colored candles just as decoration year-round.

• Open the windows while you burn candles or incense to let out harmful fumes while still enjoying ambience.

• Use an air purifier that removes both PM 2.5 and VOCs after you're done.

• Switch to a candle warmer that heats the candle and releases scent without burning. The Ozarke one listed above is a great option.

• Finally, if you must use a synthetic scent or combustion on a regular basis, just take good care of your health in other ways. Regular exercise, good nutrition, and not worrying too much are also healthy.

Incense

Is incense toxic?

Incense, despite its association with spirituality and health, is surprisingly toxic when it burns. So much so that research groups have spent time and effort quantifying exactly what chemicals, and in what amount, are released upon burning incense sticks. Most incense sticks are proprietary, meaning they won't disclose what the exact ingredients are. Typically, they are made of a combination of the following: 21% (by weight) of herbal and wood powder, 35% of fragrance material, 11% of adhesive powder, and 33% of bamboo stick. When they burn, they release 4 times the amount of Particulate Matter as a cigarette, several poisonous gases (carbon monoxide, nitrogen dioxide, and sulfur dioxide), polylcyclic aromatic hydrocarbons (PAH's), formaldehyde, and phthalates. If you must burn incense, I recommend using ones that have 100% ingredient disclosure and don't use synthetic fragrances or adhesives. Use sparingly in a well-ventilated room and use an air purifier rated to remove Particulate Matter afterward.

Is incense really toxic or is it just wellness fear?

It's not fear-mongering. Research consistently shows burning incense releases significant amounts of fine particulate matter (PM 2.5)—four times more than a cigarette—along with formaldehyde, PAHs, and other harmful compounds. That said, occasional use in well-ventilated spaces is different from daily burning in a closed room. Context matters.

Non-Toxic Air Fresheners

What can I use instead of Febreze or plug-in air fresheners?

Skip aerosols and plug-ins entirely—they release synthetic fragrances and sometimes harmful propellants like benzene. Instead, use reed diffusers with 100% essential oils, simple spray bottles (not aerosol) with essential oils diluted in water, or passive diffusers that rely on evaporation. For actual odor elimination rather than masking, open windows and use an air purifier that captures VOCs (odors) not just PM 2.5.

Are there non-toxic air freshener alternatives?

Yes. The healthiest options avoid combustion and synthetic fragrance entirely:

• Reed diffusers using 100% essential oils in a carrier oil

• Evaporative diffusers (passive or fan-based) with essential oils

• Simple spray bottles with essential oils diluted in water or witch hazel

• Candle warmers that melt candles without burning them

• Opening windows (still the best air freshener)

See my recommendations above.

What's wrong with plug-in air fresheners?

Plug-ins continuously release synthetic fragrances—often containing phthalates and other endocrine disruptors—into your air without your active control. They're essentially slow-release aerosols. The "automatic" aspect means you're getting constant, low-level exposure to whatever chemicals are in that cartridge, which typically aren't fully disclosed.

Safer Throw Methods

What is evaporation or manual diffusion?

Evaporation is when a liquid scent is naturally drawn into the air by evaporation over time, much like a puddle evaporates on a sunny day. This happens with reed diffusers, or after using a regular spray bottle (not pressurized aerosol) to spritz a scent into the air. Manual diffusion, like an electronic evaporative diffuser, promotes the same process, just faster. Think of using a small fan to encourage the scent to evaporate into the air. Evaporation and manual diffusion are the two ways in which scent moves into the air with the least manipulation, and the least change in its properties.

What is nebulized or ultrasonic diffusion?

These are common diffuser types that have the potential to change the molecular size of the scent. Some claim to make scents "nanoparticles," and while I can't verify that's truly what happens, I view them with some caution. Nanochemicals are so small, they can cross through our cell walls and even through our blood-brain barrier. The technology as a whole is very new, so while this may turn out to be a safe delivery method for scent, I still think regular evaporative diffusers like passive diffusers or fan-based diffusers, listed above, are healthier options until we know more.

What are aerosols?

Think about spray paint when you think about what aerosols are. An aerosol is technically a suspension of particles in air, and requires a fancy can with a compressed gas to propel it out of the can into a very fine mist. Aerosol scents are typically room fresheners. A variation of these is plug-in air fresheners — these use a tiny electrical circuit instead of your finger to "press the button" and release scented aerosol. (FYI, regular spray bottles are not aerosols.)

What are propellants?

Propellants are compressed gasses in aerosol cans that force the scent out in its powerful, misty form. In the "olden days," this gas was CFCs, or chlorofluorocarbons. However, CFC's were banned because they were contributing to a big hole in the ozone layer. Now, other gasses are used instead. These are released along with the scent, so it's important to use safe ones.

What is the difference between nitrogen and other gas propellants?

Harmful gasses are still used as the propellant in aerosol scent sprays. Benzene, a well-known human carcinogen, of which there is no level of safe exposure to, was found in many personal care aerosol sprays in 2021, forcing a major recall of those items. Ethanol may be a propellant that contains trace amounts of benzene (a carcinogen). Some home fragrance aerosols use acetone and propane as propellants.

And yes, while it is true that these are released in such small amounts that one spray will not individually cause harm to you, I generally don’t think of exposures that way. We are constantly being exposed to poor air quality, so if you can make this change without added stress, I think it’s a good idea. You can read more about my philosophy on the About Interior Medicine page.

Nitrogen gas is currently considered the safest gas propellant. It is generally considered non-toxic and safe as part of an aerosol can. So, avoid aerosols as scent delivery systems whenever you can. If you read the Safety Data Sheet and it specifically shows Nitrogen is the propellant, it is less harmful than other options.