Scented cleaning products generate invisible indoor air pollution

Research led by Purdue University indicates that scented cleaning products, including both conventional and botanical essential oil-based varieties, can create significant indoor air pollution. Fragrances containing terpenes—such as pinene, limonene, thymol, and linalool—react rapidly with ozone to form ultrafine nanoparticles.

These particles, often measuring between 1 and 30 nanometres, are small enough to penetrate deep into the respiratory system. The study found that cleaning activities like mopping, spraying, and wiping can generate billions or trillions of these nanoparticles. The resulting respiratory dose can be comparable to, or even greater than, the exposure experienced near busy roads.

Because these particles are invisible and do not produce smoke or haze, they often go unnoticed by residents and many domestic air quality monitors. To mitigate exposure, researchers suggest using unscented products, utilizing exhaust fans, and avoiding ozone-generating devices during cleaning tasks.