Air fresheners have become part of modern routines—at home, in cars, even at the office. Pine-scented clips on vents, automatic sprays in hallways, or a lavender candle glowing in the evening make spaces feel fresh. But are these products really safe for our health?
What’s Really Inside Air Fresheners?
Air fresheners come in many forms—sprays, gels, candles, and essential oil diffusers. What they all share are volatile organic compounds (VOCs). Indoors, these chemicals don’t simply vanish. They react with ozone that enters through ventilation, creating ultrafine nanoparticles.
Engineers at Purdue University warn that these particles can be as small as one nanometer—tiny enough to penetrate deep into the lungs and spread to other organs.
Experiments in Purdue’s “tiny house lab” revealed that so-called non-toxic wax melts polluted indoor air just as much as regular candles. Terpenes—the compounds that give scents their fragrance—react rapidly with ozone, producing nanoparticles in concentrations comparable to car exhaust.
Harmful Ingredients to Watch Out For
VOCs are only part of the story. A European Consumers Union study found that many air fresheners release benzene and formaldehyde, both linked to cancer. Other common ingredients include limonene, a fragrance compound that can trigger allergies or asthma attacks.
Even more troubling are phthalates (pronounced thal-ates), chemicals tied to hormone disruption, reproductive problems, and developmental issues. A study by the Natural Resources Defense Council (NRDC) detected phthalates in 86% of products tested—including those labeled “all-natural” or “unscented.” None listed the chemicals on their labels.
The U.S. Centers for Disease Control and Prevention (CDC) reports that most Americans carry at least five different phthalates in their bodies. Although individual levels are low, experts caution that combined exposure can act like a high dose, compounding risks.
Research in New York and Krakow confirmed that the more phthalates present in the air, the higher the levels of phthalate metabolites found in residents. In other words, the chemicals we breathe indoors don’t just float away—they end up inside our bodies.
Health Risks You Might Not See
The danger goes beyond unpleasant odors. Nanoparticles and VOCs can irritate the eyes, nose, and throat, while long-term exposure has been linked to asthma, cardiovascular disease, and certain cancers.
An Irish study found that scented candles, incense, and indoor smoking can raise particle levels to 15 times above World Health Organization safety limits. In poorly ventilated spaces, pollution lingers for hours.
Daily habits also matter. Within just 20 minutes of exposure to scented products, scientists estimate that between 100 billion and 10 trillion nanoparticles may settle into the respiratory system—a staggering load for something barely perceptible.
Is a "Natural" Air Freshener Safer?
Many consumers turn to “natural” air fresheners, believing they are safer. But experts warn that burning natural ingredients can also release harmful pollutants. These compounds may react with ozone to form toxic byproducts.
Research on natural alternatives remains limited, and some adverse effects might not appear until years of chronic exposure. Regulators are being urged to strengthen testing and set clearer safety standards, especially for products used around children and pregnant women.
Safer Ways to Keep the Air Fresh
There are simple ways to reduce risks without giving up comfort. Experts recommend:
- Ventilation first. Open windows and doors regularly. Fresh outdoor air is far better than artificial scents.
- Limit use. Save air fresheners or candles for larger, well-ventilated spaces, not small bathrooms or bedrooms.
- Choose carefully. Some products, like certain brands of sprays, contain fewer phthalates. Look for fragrance-free cleaning options.
- Snuff outdoors. Blow out candles outside if possible, most of the harmful smoke comes right when the flame is extinguished.
- Try natural alternatives. Instead of masking smells, remove the source. Baking soda, vinegar, or simply better airflow can reduce odors without chemicals.
Air fresheners may make homes, cars, and offices smell pleasant, but behind the pine, lavender, or vanilla lies a complex cocktail of nanoparticles and chemicals.
As an assistant professor in Purdue’s Lyles School of Civil and Construction Engineering, Nusrat Jung explains that fragranced products are not just passive sources of pleasant scents; they actively alter indoor air chemistry.
So before you spray or strike a match, think twice. The cleanest, healthiest scent may still be the simplest, which is fresh air.
Sources:
https://theconversation.com/how-home-fragrances-can-impact-indoor-air-quality-and-your-health-244221
https://www.bbc.co.uk/programmes/articles/58KFJzpJb2kyLtDPhhHqnbQ/are-perfumed-products-bad-for-me
https://www.news-medical.net/news/20250217/Research-shows-the-unseen-danger-of-air-fresheners-and-cleaning-products.aspx
https://www.researchgate.net/publication/262872839_Clearing_the_Air_Hidden_Hazards_of_Air_Fresheners
