A study by École Polytechnique Fédérale de Lausanne (EPFL) has highlighted the significant effects of personal care products on indoor air quality.
The research, published in Environmental Science & Technology Letters, demonstrates how common products like deodorants, perfumes, and dry shampoos emit a mixture of volatile organic compounds (VOCs) that can lead to the formation of harmful airborne particles when they interact with ozone.
The research team and Dusan Licina, tenure-track assistant professor and head of the Human-Oriented Built Environment Lab (HOBEL) at EPFL, focused on five widely used products: roll-on deodorant, spray deodorant, hand lotion, perfume, and dry shampoo hair spray. These products, all selected from major European retailers, were tested in environmental chambers designed to simulate real indoor environments.
In the controlled experiment, scientists released each product in the chamber under two scenarios. In the first, they monitored air quality after product use alone. In the second, they introduced ozone, a reactive gas that infiltrates indoor spaces through open windows and even originates from common office devices like laser printers. By using a variety of precise measurement tools, they observed the concentrations and types of gases and particles emitted.
The findings revealed that, even in the absence of ozone, these products released over 200 VOCs. These compounds include ethanol and monoterpenes, which are prevalent in personal care products. However, when ozone was introduced, a more complex picture emerged. Chemical reactions between the VOCs and ozone generated new pollutants, including ultrafine particles that often exceeded levels found in highly polluted urban areas, such as downtown Zurich.
Licina highlighted the potential health implications, noting: “Some molecules nucleate – in other words, they form new particles that can coagulate into larger ultrafine particles that can effectively deposit into our lungs.” He added, “In my opinion, we still don’t fully understand the health effects of these pollutants, but they may be more harmful than we think.”
The team found that perfumes and aerosol sprays, in particular, produced high levels of new particles in the presence of ozone. These findings are especially concerning given that many people use these products daily in confined spaces like bathrooms, where ventilation is often limited.
The researchers recommend several steps to reduce the impact of personal care products on indoor air quality. One solution is improving ventilation during and immediately after using these products. Another option is incorporating air purification technologies, such as activated carbon-based filters, which can help to capture VOCs and other pollutants before they spread indoors. Additionally, limiting ozone exposure within homes and workspaces could minimize the formation of these secondary pollutants.
However, Licina also pointed to the need for behavioral changes: “I know this is difficult to hear, but we’re going to have to reduce our reliance on these products or, if possible, replace them with more natural alternatives that contain fragrant compounds with low chemical reactivity.” He added that raising awareness among healthcare providers and people who work with vulnerable populations, such as children and the elderly, could help mitigate potential health risks.
While the exact health effects of long-term exposure to these ultrafine particles remain unknown, the EPFL team’s findings underscore the importance of understanding how everyday personal care routines can influence the air quality within our homes. As research continues, both consumers and product manufacturers may need to re-evaluate the compounds used in personal care products and explore options that reduce their chemical reactivity, especially in indoor environments.
Licina concluded: “This is an area where new toxicological studies are needed.” By deepening our understanding of these interactions, researchers hope to inform future policies and product formulations that could make indoor spaces healthier for everyone.
Journal Reference:
Tianren Wu, Tatjana Müller, Nijing Wang, Joseph Byron, Sarka Langer, Jonathan Williams, and Dusan Licina, ‘Indoor Emission, Oxidation, and New Particle Formation of Personal Care Product Related Volatile Organic Compounds’, Environmental Science & Technology Letters 11 (10), 1053-1061 (2024). DOI: 10.1021/acs.estlett.4c00353
Article Source:
Press Release/Material by École Polytechnique Fédérale de Lausanne (EPFL)
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