woman spraying air freshener in a house

Do Air Fresheners Impact Our Health?

February 5, 2024

Air fresheners are commonly used indoors to cover unpleasant odors or just to give a room a pleasant scent. But have you ever really thought about how they worked, the ingredients in them, and how they might impact our health?

Marianthi-Anna Kioumourtzoglou, ScD, is an associate professor of environmental health sciences with expertise in the health impacts of commercial products. To learn more about air fresheners and their possible hazards, we spoke with Dr. Kioumourtzoglou. Here’s what she had to say.

What is an air freshener? What do air fresheners do?

Generally speaking, air fresheners are a class of commercial products that emit a scent or fragrance. They can do this in various ways, but the result is the same: a pleasant smell for a home, office, restroom, etc.

Sometimes, people use air fresheners simply to add a pleasant scent to an enclosed space. In other cases, people use air fresheners to mask unpleasant odors. In that scenario, the intent is to overwhelm our olfactory sense with a more pleasing scent or fragrance.

Do all air fresheners work the same way? What are some of the different mechanisms?

Air fresheners disperse their scents in several ways. Some air fresheners come as an aerosol and are sprayed. Some require a heat source, such as a candle flame or the electric current from a wall outlet. Others vaporize their scent at room temperature. You’ve probably seen examples of these hanging in cars and taxis.

What would a chemical analysis of air fresheners tell us? What compounds do air fresheners emit?

Air fresheners are not strictly regulated, so there is a wide range of ingredients and concentrations of ingredients in them. That said, there are a few ingredients that are commonly used in air fresheners. Here are a few that stand out:

  • Volatile Organic Compounds (VOCs): The amounts of individual VOCs will vary by the fragrance composition, but generally, these include formaldehyde, acetaldehyde, benzene, toluene, and a few others. For example, alpha-pinene is commonly used in pine-smelling fresheners to give the clean and fresh smell of pine trees. Interestingly, alpha-pinene occurs naturally in the environment but can also be synthesized.
  • Phthalates: Chemicals that embed a fragrance in plastic or wax so the fragrance can later be released when the air freshener is unpackaged and used.
  • Propellants: These are hydrocarbons that deliver fragrance as a very fine mist.
  • Solvents: Chemicals used to dissolve the fragrance and other ingredients in a liquid, which eventually evaporates into the air.
  • Aldehydes: Chemicals that form after an air freshener has been released into the air. After several hours, many of the ingredients listed above react with other molecules in the air to become aldehydes and other secondary VOCs.
  • Deodorizers: Chemicals that can absorb or neutralize odors.

Can any of these substances affect our health?

While most people can tolerate occasional exposure to air fresheners and deodorizers at low concentrations, people with allergies or asthma may get irritated eyes and throat, headaches, or even an asthma attack.

There is some evidence that long-term use of air fresheners can affect heart function, especially in individuals who also have lung disease. We have learned, too, that air fresheners can affect a person’s balance of hormones, which can impact reproductive health. And there is growing evidence that phthalates, aldehydes, and 1,4-dichlorobenzene (a common deodorizer) can cause cancer.

So, yes, air freshener components (either directly emitted from the air freshener or indirectly formed by subsequent indoor chemical reactions) have been linked to numerous adverse health outcomes. However, since there are many other sources of the same chemicals in our indoor environments, it’s difficult to disentangle specific sources and attribute risks accordingly.

If I want to avoid using air fresheners and deodorizers, what are some other fresh fragrance strategies I could use?

There are many things we can all do to reduce unpleasant odors while improving the air quality of our indoor environments. And none of them require commercial air fresheners! Here are a few suggestions:

  • Clean and well-ventilated spaces tend to have lower (or no) unpleasant odors. Personally, I open my window daily in the morning for 15-30 minutes and most times when I cook. Having said that, it is also important to note that opening the window allows outdoor air in, so it’s best to avoid opening windows during rush hours when traffic-related pollution is highest or during extreme air pollution days (e.g., because of wildfires)
  • Remove sources of odors such as rotting food, cat litter, damp towels, etc. Empty the garbage often. And, keep an open box of baking soda in the fridge.
  • Learn to love plants. Fragrant plants such as jasmine, roses, or lilies add visual beauty, as well as their fragrance to your home. Plants can also help purify indoor air by absorbing VOCs. So, a simple fern can actually improve a room’s air quality!


Marianthi-Anna Kioumourtzoglou, ScD, is an associate professor in the Department of Environmental Health Sciences at the Mailman School of Public Health.