Scented Cleaning Products Produce Pollution That Reaches the Lungs

Researchers from Purdue University in the United States have found that cleaning products scented with essential or synthetic oils may pose a risk to indoor air quality and public health.

The study reported that the compounds responsible for the fragrances in these products, known as terpenes, readily react with indoor ozone to form tiny nanoparticles that can penetrate deep into lung tissue and enter the bloodstream.

Brandon Burr, the study’s lead researcher, explained that while cleaning removes germs from surfaces, it can generate invisible air pollution. He noted that the resulting nanoparticles carry a respiratory dose similar to or greater than what a person might inhale while standing next to a busy highway.

The team conducted their experiments inside a “miniature laboratory house” and found that the products used produced billions of nanoparticles (with diameters of 1–30 nanometers) within minutes. This size is undetectable by most air quality monitors, meaning people may inhale them without realizing it.

The danger of these nanoparticles lies in their ability to reach deep lung tissue. Some studies have linked excessive exposure to limonene, which gives citrus scents, to conditions that precede heart disease and diabetes.

Although terpenes are natural compounds found in the scents of pine, thyme, and lavender, their concentrations in cleaning products can be tens of times higher than what a person inhales in nature.

Burr noted that the reaction resembles the processes that produce smog on highways, warning that air may appear clean and smell pleasant while being contaminated with invisible particles. He concluded with practical recommendations: use unscented cleaning products, ventilate rooms during cleaning, and avoid ozone-generating devices marketed as air purifiers.

The researchers presented the findings of this study at the American Chemical Society (ACS) Fall Meeting, held from August 23 to 27.