The Hidden Air Quality Risks of Scented Cleaning Products

The fresh scent of citrus, pine, or floral notes in your home often conveys cleanliness. However, what many may not realize is that these pleasant fragrances are linked to complex chemical reactions in the air that can produce harmful nanoparticles.

A study led by Brandon Boor at Purdue University highlights how both conventional cleaners and essential oil-based products release fragrance compounds that react quickly indoors, generating nanoparticles that can be inhaled deeply into the lungs.

According to Boor, using scented products can turn everyday cleaning tasks into a source of invisible air pollution. "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," he explained during the recent fall meeting of the American Chemical Society.

The Science Behind Nanoparticle Formation

Cleaning agents often contain compounds like pinene (from pine), limonene (lemon), thymol (thyme), and linalool (lavender). In high concentrations—much higher than those typically found outdoors—these terpenes can react with indoor ozone to yield nanoparticles. Boor pointed out that the concentrations of these particles can reach levels tens or even hundreds of times greater than in a forested area.

The research team conducted experiments in a model home to understand this indoor atmospheric chemistry under realistic conditions. They simulated typical cleaning activities such as mopping and wiping down surfaces, revealing that these tasks lead to the rapid generation of billions or trillions of particles. Notably, most of these were ultrafine particles, measuring between 1-30 nanometers in diameter.

Health Implications of Ultrafine Particles

The tiny size of these particles raises significant health concerns. Ultrafine particles can travel deep into the respiratory system, potentially irritating and inflaming lung tissues. Some particles may even move into the bloodstream, meaning that indoor air pollution from cleaning products could have serious health repercussions.

Surprisingly, the nanoparticle formation occurs very quickly, often within minutes of starting cleaning. "By the time you finish cleaning up an indoor space, you've already formed a lot of nanoparticles and inhaled them," Boor stated, shedding light on the immediate risks posed by these products.

The Ozone Factor

In recent studies, Boor and colleague Ernest Blatchley examined the combined effects of using scented surface cleaners alongside UV-C lamps designed for disinfection. This combination produced conditions highly conducive to further nanoparticle formation, as the lamps generated ozone—a potent reactive gas that accelerates the reactions with terpenes.

During these experiments, ozone concentrations reached levels comparable to those found outside in urban areas, further complicating the air quality issue within enclosed spaces. The intensified conditions greatly enhanced nanoparticle production, raising alarms about the inhalation risks for occupants.

Practical Recommendations for Improvement

While the findings may seem alarming, Boor emphasizes the importance of cleaning for surface disinfection. The goal isn't to deter people from cleaning but rather to promote informed choices. To mitigate the risks of secondary pollution while cleaning, several recommendations arise:

• Opt for unscented cleaning products.
• Improve ventilation with the use of exhaust fans or by opening windows during cleaning.
• Avoid devices that generate ozone when using scented products.

These simple measures can significantly reduce exposure to the harmful nanoparticles created during the cleaning process.

In conclusion, while scented cleaning products evoke a sense of cleanliness, the hidden risks they pose to air quality and respiratory health warrant serious consideration. The ongoing research into indoor air pollution underscores the necessity for consumers to be vigilant about their product choices as well as the conditions under which they use them.

Boor extends his gratitude to the graduate and undergraduate students who supported the tiny house experiments. This research received funding from the National Science Foundation Faculty Early Career Development Program and the Alfred P. Sloan Foundation.

Materials provided by American Chemical Society. Content may be edited for style and length.