That Fresh Cleaning Smell May Fill Your Home With Harmful Nanoparticles: Study

Scented cleaning products may make homes smell fresh, but they can also rapidly generate tiny airborne particles that may reach deep into the lungs, according to research from Purdue University.

The study, presented at an American Chemical Society meeting, examined how fragrance compounds released by conventional cleaners and botanical products react with ozone indoors.

Many scented cleaning products contain chemicals called terpenes, including limonene, pinene, thymol and linalool. When these compounds react with ozone in the air, they can form new particles.

Researchers tested cleaning activities such as mopping floors, spraying countertops and wiping surfaces inside a model home designed to resemble an ordinary house. They found that cleaning could generate billions or even trillions of particles, depending on the product.

Most of the particles were ultrafine particles measuring about 1–30 nanometres. Because these particles are extremely small, many household air-quality monitors may not detect them.

The researchers said the particles can penetrate deep into the respiratory system. Ultrafine particles may contribute to irritation and inflammation, although the study did not establish specific health effects from the particles produced during household cleaning.

Particle formation occurred within minutes of using scented products. The researchers also found that higher indoor ozone levels could intensify nanoparticle formation. In experiments involving ozone-producing disinfection devices, the combination of ozone and fragrance compounds resulted in greater particle production.

The findings suggest that indoor air chemistry can change quickly during routine cleaning, even when there is no visible smoke, dust or haze. Researchers emphasised that cleaning remains important for removing germs from surfaces.

However, they suggested several ways to reduce exposure to the particles. These include choosing fragrance-free or low-fragrance cleaning products, improving ventilation by opening windows or using exhaust fans, and avoiding the simultaneous use of scented cleaners and ozone-generating devices.

REFERENCE: American Chemical Society. "That fresh cleaning smell could be filling your home with nanoparticles." ScienceDaily. ScienceDaily, 26 September 2026.