Your Perfume Could Be Destroying Your Body’s Invisible Air Shield

Perfumes and lotions disrupt the body’s natural air chemistry, weakening a protective ozone barrier created by skin-oil reactions.

Fragrances and lotions do more than change how people smell. They actively influence the air chemistry around the wearer, disrupting a vital natural process the body uses to protect itself from pollution, according to an international research team that includes scientists from Penn State.

In a new study published in the journal Science Advances, the researchers found that personal care products such as perfumes and even unscented lotions change the chemical makeup of the “human oxidation field,” a natural protective air layer surrounding a person’s breathing zone and skin.

The study indicates that these products interfere with the way skin oils normally react with indoor ozone to generate highly reactive hydroxyl (OH) radicals. These radicals are essential for forming an invisible chemical shield around the body that helps protect against ozone exposure, explained Donghyun Rim, associate professor of architectural engineering at Penn State and a co-author of the study.

Complex chemistry of ozone and skin oils

“Think of people as candlelight, our body temperature is typically the warmest thing in the indoor environment,” he said. “We’re constantly pulling the air around us toward us, creating chemical reactions in the immediate area around our bodies — a phenomenon we call the human oxidation field. Our skin can absorb ozone, which is beneficial because it prevents us from inhaling ozone directly.”

But it may not be entirely beneficial, he added. The process is complex. When skin reacts with ozone and produces OH radicals, it sets off secondary reactions that release new chemicals into the air we breathe.

“We still don’t fully understand the impact of these byproducts,” Rim said. “But we’re working to understand it.”

People spend up to 90% of their time indoors, making indoor air quality a major factor in humans’ overall exposure to chemical pollutants. Even just by being in a room with ozone, a common air pollutant that can enter indoors from outside, our bodies react with it, he explained.

Controlled experiments in ozone chambers

In the study, the research team conducted experiments where volunteers sat in a controlled chamber with ozone present. The researchers first measured the OH field created by the volunteers without using personal care products. Then they repeated the experiments after the volunteers applied either a common unscented body lotion or a popular fragrance.

Rim’s team, which helped discover the human oxidation field in 2022, developed a three-dimensional computational fluid dynamics model to simulate the evolution of the human oxidation field, which made it possible to see the impact of personal care products.

They found that applying the products substantially disrupted the natural human oxidation field. Specifically, the application of unscented lotion caused a roughly 170% increase in OH reactivity, which led to a roughly 140% decrease in OH concentrations around the wearer, meaning their natural ozone barrier was less than half as strong because the OH radicals were floating off into the air instead of forming a protective force field.

Fragrance effects fade faster than lotion

The researchers found that the effects of lotion tend to be more persistent over time compared to fragrance. The fragrance effects were stronger initially but less persistent than lotions, as the organic compounds in fragrances, like ethanol, broke down more rapidly into the gas phase and were dispersed more broadly into the air.

“The application of a fragrance and a lotion together showed that fragrances impact the OH reactivity and concentration over shorter time periods, whereas lotions show more persistent effects, consistent with the rate of emissions of organic compounds from these personal care products,” Nora Zannoni, researcher at the Institute of Atmospheric Sciences and Climate in Bologna and lead author on the study, said.

Reference: “Personal care products disrupt the human oxidation field” by Nora Zannoni, Pascale S. J. Lakey, Youngbo Won, Manabu Shiraiwa, Donghyun Rim, Charles J. Weschler, Nijing Wang, Tatjana Arnoldi-Meadows, Lisa Ernle, Anywhere Tsokankunku, Gabriel Bekö, Pawel Wargocki and Jonathan Williams, 21 May 2025, Science Advances.
DOI: 10.1126/sciadv.ads7908

The Alfred P. Sloan Foundation funded the Penn State aspects of this research.

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