Deodorants And Perfumes Change The Chemical Composition Of The Air We Breathe

Using scented chemicals exposes us to a wide range of toxic substances: Purdue University study on indoor air quality.

Air fresheners, scented candles, disinfectants, floor cleaners, hair care products: we use them every day without thinking that the fresh scents that remind us of forests and meadows are actually chemical compounds that are far from the naturalness they are trying to create.

In a series of studies analyzing indoor air quality , Purdue University engineers found that using chemically produced perfumes quickly fills the air with nanoparticles small enough to penetrate deep into the lungs. The researchers’ experiments, conducted in a first-of-its-kind home lab, also showed that these products produce more nanoparticles than gas stoves and car engines, and that they can settle in our airways after just 20 minutes of exposure.

Chemistry, Fragrances, and Air Quality: Purdue Research

When we enter a home, we all want to smell nice . However, the fresh scents of pine, mint, and tea tree that fill the coziness of our homes are not always as natural as they seem.

In many cases, deodorants and fragrances owe their eco-friendliness to chemical compounds created in laboratories. And when using these types of products, the scent that spreads throughout the room quickly fills the air. Nanoparticles are small enough to penetrate our lungs. These particles are formed when fragrances interact with ozone, which is naturally present in the environment and penetrates into buildings through windows and ventilation systems.

Purdue University scientists explain that the collision of volatile nanoparticles and ozone triggers a chemical reaction that produces new pollutants. As Nusrat Jung , a professor in the Lyles School of Civil Engineering and Engineering, noted,

“The forest is a pristine environment, but if you use cleaning products and aromatherapy products that contain chemical fragrances to recreate the forest atmosphere in your home, you are actually creating a huge amount of indoor air pollution that you shouldn’t be breathing.”

Other studies have shown that sprays and other commonly used products emit volatile organic compounds that can be potentially harmful to health, but Jung and his colleague Brandon Boer are the first to study the formation of airborne particles at the nanoscale in a closed environment and compare it to external atmospheric processes. And the results of their experiments paint a very clear picture.

Home laboratory for studying household contaminants

To study outdoor air quality in detail, Jung and Boer used Purdue’s Zero Energy Design Guidance for Engineers (zEDGE) lab, a small home workshop that has all the features of a typical home but is equipped with the latest sensors to monitor volatile chemicals. As Boer explains,

“To understand how indoor air particles are formed, we need to measure the smallest nanoparticles, down to one nanometer. At this scale, we can see the early stages of new particle formation, when fragrances react with ozone to form clusters of small molecules. These clusters quickly evolve, grow, and change in the air around us.”

With this level of detail, which allows us to use data with unprecedented precision , researchers have found that many everyday products may be less safe than previously thought.

Health Effects The exact reason for inhaling these chemicals is not yet clear, but Purdue engineers have found that the chemicals react very quickly with ozone, releasing large quantities of nanoparticles that can reach very high concentrations.

“Our research shows that scented products are not just passive sources of pleasant aromas, but also actively change the chemical composition of indoor air, resulting in the formation of nanoparticles at concentrations that can have serious health consequences,”

said Jung. The researchers say these processes need to be taken into account when designing buildings and their ventilation systems to reduce our exposure to potentially harmful substances.

Perfumes produce more nanocluster aerosols than cars

In a recent study , researchers at Purdue University found that scented candles , which are typically advertised as non-toxic because they don’t burn, are actually just as polluting as traditional candles. Melted wax actually contains a higher concentration of essential oils than wax, and so emits a pleasant aroma. It also contains higher levels of terpenes , the chemical compounds found in fragrances and perfumes that interact dangerously with ozone.

So it’s not enough to study just combustion-related nanoparticle formation; we should also focus on aromatic chemicals, which don’t require fire to form. But the list of household pollutants is even longer: In another study, Jung and Buhr found that essential oil diffusers, disinfectants, air fresheners, and other scented sprays also produce large amounts of nanoparticles.

Even simply cooking on a gas stove can lead to indoor air pollution: if we consider particles smaller than 3 nanometers, it turns out that one kilogram of heating oil emits 10 quadrillion particles, which is comparable to the amount emitted by a car’s internal combustion engine .

However, as the researchers explain, aromatic chemicals outperform gas stoves and car engines in terms of emissions. Nano-cluster aerosols (i.e. particles smaller than 3 nanometers): just 20 minutes of exposure to this product can deposit between 100 billion and 10 trillion of these particles in our respiratory system.

Pollution research for healthier indoor environments

Purdue’s tiny home lab , which creates a more realistic environment than the facilities typically used for indoor air quality research and product development, allows researchers to collect high-resolution data on the rate of formation and growth of new particles in a closed environment. The opportunity they both took advantage of was to study the effects of a range of daily household activities on indoor air quality.

For example, Jung and his students found that in a single home hair care session we can inhale between 1 and 17 milligrams of volatile compounds such as volatile cyclic methylsiloxane, which is found in many shampoos, conditioners, sprays, creams, lotions, gels, oils, and waxes for straightening and curling hair.

“Indoor air quality is often overlooked when designing and managing the buildings we live and work in, yet it has a direct impact on our health every day. Using data from a tiny home lab, we aim to close this gap by turning fundamental research into real-world solutions for healthier indoor environments for everyone.”

Boer said. In short, the researchers hope their findings could lead to better monitoring , control and even regulation of indoor air quality, for which there are currently no specific regulations.