Fragrances in common cleaning products react with ozone to create indoor air pollution by forming nanoparticles that can settle deep in the respiratory system.
RT’s Three Key Takeaways:
- Nanoparticle Formation: Scented cleaning products react with indoor ozone to create ultrafine particles at concentrations that can exceed outdoor pollution levels.
- Respiratory Health Risks: These nanoparticles are small enough to deposit deep within the airways, potentially causing respiratory system irritation, inflammation, or entry into the bloodstream.
- Preventative Measures: Researchers recommend using fragrance-free products, increasing ventilation, and avoiding ozone-generating devices like certain UV-C lamps during cleaning to reduce exposure.
Fragrances used in surface cleaners and disinfectants react with indoor ozone to form invisible nanoparticles at levels comparable to or higher than city traffic, according to research presented at the American Chemical Society (ACS) fall meeting.
The findings suggest that routine cleaning can generate ultrafine particle pollution that travels deep into the lungs.
“Importantly, cleaning removes viruses and bacteria from surfaces, but it can also generate invisible air pollution. There’s no visible dust or smoke in the air, but these particles are forming,” said Brandon Boor, an assistant professor of civil and construction engineering at Purdue University.
The researchers found that terpenes—scent compounds like pinene and limonene found in both conventional and botanical products—evaporate and react with ozone. While these reactions occur naturally in forests, indoor terpene concentrations during cleaning can be tens to hundreds of times higher than those found in nature, according to the research team.
Testing in a model house showed that mopping or spraying countertops formed billions or trillions of particles, most ranging from 1 to 30 nanometers wide. This size is often too small for standard at-home air quality monitors to detect but large enough to contribute to respiratory irritation and inflammation.
“We showed that indoor ozone reactions with fragrances from cleaning produce nanoparticles that carry a respiratory dose comparable to, or greater than, what you would experience from standing outside along a busy road,” said Boor.
The study also noted that using germicidal far-UV (UV-C) lamps alongside scented cleaners can intensify particle formation. These lamps interact with oxygen to generate ozone, which accelerates the chemical reaction with terpenes.
To mitigate risks in healthcare and residential settings, the team recommended choosing fragrance-free products, running exhaust fans, and avoiding the simultaneous use of ozone-generating devices and scented cleaners.
