Air fresheners contain a complex mix of volatile organic compounds, solvents, propellants, and fragrance chemicals, many of which never appear on the label. A survey of scented consumer products found they collectively emitted more than 100 volatile organic compounds, yet only ethanol was listed on any product label, and only for two products. What you smell is just the surface of a much longer ingredient list.
Fragrance Chemicals
The scent itself comes from a blend of natural or synthetic fragrance compounds. The most commonly detected are limonene (a citrus scent), alpha- and beta-pinene (pine scents), and terpenes like linalool, geraniol, and citronellol. These are the same types of molecules found in essential oils, and they show up in both “natural” and conventional products.
Synthetic musks add depth and longevity to the scent. The most widely used are Galaxolide and Tonalide, polycyclic musk compounds found in air fresheners, detergents, and perfumes. These chemicals are persistent enough to accumulate in the environment. Lake Ontario sediments alone contain an estimated 16,000 kg of Galaxolide, with roughly 49 kg deposited each year. That persistence is part of what makes them effective at producing a long-lasting scent, but it also means they linger in waterways and indoor dust long after use.
Manufacturers rarely disclose individual fragrance ingredients. The word “fragrance” on a label can represent dozens of separate chemicals blended together.
Solvents, Carriers, and Fixatives
Fragrance compounds need something to dissolve in and something to help them last. Ethanol and acetone are the most common carrier solvents, helping disperse the scent into the air. Diethylphthalate (DEP) serves as a fixative, slowing evaporation so the fragrance lingers longer. DEP is the only phthalate still commonly used in fragranced products, according to the FDA.
Aerosol air fresheners also contain hydrocarbon propellants, typically butane and propane, which create the pressure that forces the product out of the can as a fine mist. These gases evaporate almost instantly after spraying.
Odor-Neutralizing Agents
Some air fresheners don’t just cover up smells. They claim to eliminate them. Products like Febreze use cyclodextrins, ring-shaped sugar molecules with a hollow center that traps odor-causing compounds inside. The cyclodextrin essentially wraps around the smelly molecule, locking it in place so it can no longer reach your nose. This is a genuinely different mechanism from simply layering a stronger scent over a bad one, though most products combine both approaches.
Hazardous Compounds You Won’t See on the Label
Close to half of the scented products tested in one major survey generated at least one carcinogenic hazardous air pollutant. The chemicals of concern included acetaldehyde, formaldehyde, 1,4-dioxane, and methylene chloride. None of these were listed on labels. Some are byproducts of the manufacturing process rather than intentional ingredients, but they end up in your indoor air regardless.
The chemistry doesn’t stop once you spray. Limonene and other terpenes react with ozone already present in indoor air, creating secondary pollutants including aldehydes, ketones, carboxylic acids, and other oxygenated organic chemicals. Lab studies have shown these reaction products trigger inflammatory responses in lung cells. So the chemical composition of what you breathe after using an air freshener is different from what was actually in the can.
How These Ingredients Affect Health
The volatile organic compounds in air fresheners, including limonene, pinene, acetaldehyde, and formaldehyde, are known respiratory irritants. Among people with asthma, 41% report health problems specifically from air fresheners or deodorizers. The most common complaints are respiratory difficulties (43.3% of affected asthmatics) and mucosal symptoms like eye, nose, and throat irritation (27.2%). Beyond breathing problems, fragranced products have been linked to migraine headaches, contact dermatitis, and neurological symptoms.
These effects aren’t limited to people with diagnosed conditions. Nearly 40% of the general population in one study said they would leave a business as quickly as possible because of air fresheners or fragranced products. About 37% reported being unable to use a public restroom with an air freshener inside.
“Natural” Air Fresheners Use Similar Chemistry
Products labeled natural, green, or organic typically use essential oils instead of synthetic fragrance blends. Essential oils are complex mixtures of terpenes and other aromatic compounds extracted from plants. Monoterpenes make up about 90% of most essential oils, and the key fragrance molecules (geraniol, linalool, limonene, citronellol) are the same compounds found in synthetic versions.
This means “natural” air fresheners emit many of the same volatile organic compounds as conventional ones. They can still react with indoor ozone to form secondary pollutants. Only about 29% of asthmatics were aware that natural and organic fragranced products typically emit hazardous air pollutants. The source of the chemical matters less than what it does once it’s airborne in your home.