Hidden Dangers in Your Home: Fragranced Products and Cooking Pose Health Risks
When you step into a pine forest, the crisp, fresh scent is invigorating. However, recreating this scent indoors using chemical products like air fresheners, wax melts and candles can have unintended consequences. According to recent studies by Purdue University engineers, these products can significantly pollute indoor air, posing potential health risks.
The Formation of Nanoparticles
The issue arises when fragrances from these products interact with ozone, which enters homes through ventilation systems. This interaction triggers chemical reactions that produce nanoscale particles small enough to penetrate deep into the lungs. These nanoparticles can spread to other organs, posing serious health concerns.
Nusrat Jung, an assistant professor at Purdue's Lyles School of Civil and Construction Engineering, emphasizes the irony of using chemically manufactured scents to recreate a pristine environment like a forest indoors. "You're actually creating a tremendous amount of indoor air pollution that you shouldn’t be breathing in," Jung notes.
The Tiny House Lab: A Breakthrough in Indoor Air Quality Research
To study indoor air quality comprehensively, Jung and fellow professor Brandon Boor utilize a unique "tiny house lab" at Purdue University. This dedicated residential lab space is equipped with advanced air quality instruments, allowing researchers to track how household products emit volatile chemicals and generate nanoparticles.
The lab, known as the Purdue zero Energy Design Guidance for Engineers (zEDGE) lab, was built in 2020 and features all the amenities of a typical home. It provides an unprecedented level of detail and accuracy in monitoring the impact of everyday activities on indoor air quality.
Flame-Free but Not Risk-Free: The Truth About Scented Products Indoors
In a recently published paper, the pair discovered that scented wax melts—often marketed as “nontoxic” because they’re flame-free—can actually pollute indoor air as much as traditional candles. Wax melts contain a high concentration of fragrance oils that release terpenes, the compounds that create those pleasant scents. When terpenes react with ozone, they rapidly form harmful nanoparticles.
Other studies by the pair prevealed that essential oil diffusers, air fresheners, disinfectant sprays, and other fragranced products also produce significant nanoparticle emissions.
Cooking: Another Major Contributor to Indoor Pollution
It’s not just scented products that are problematic. Cooking on a gas stove is another major source of indoor nanoparticle pollution. Research shows that burning just one kilogram of cooking fuel can release up to 10 quadrillion particles smaller than 3 nanometers—comparable to or even exceeding emissions from car engines.
In fact, indoors, you may inhale 10 to 100 times more of these particles than you would while standing on a busy street.
Whether from scented products or cooking, the air inside your home can become heavily polluted—sometimes even more than outdoor traffic air. These findings underscore the need for greater awareness and further research on the hidden sources of indoor air pollution.
Pushing Innovation: Testing New Air Quality Tools
To stay ahead of the curve, Jung and Boor are working with industry partners to test innovative air quality instruments before they hit the market. One such tool is the Particle Size Magnifier–Scanning Mobility Particle Sizer (PSMPS), developed by GRIMM AEROSOL TECHNIK of the DURAG GROUP. This device allows them to detect particles as small as one nanometer, enabling real-time tracking of particle formation and growth.
Thanks to high-resolution data from the lab, the team has been able to compare indoor nanoparticle formation with outdoor environments—an essential step in understanding pollution exposure and improving health outcomes. Since indoor air remains largely unregulated and understudied, this research fills a crucial knowledge gap.
The lab is also being used to study air pollution from everyday personal routines like hair care. For instance, Jung’s team found that certain chemicals—especially cyclic volatile methyl siloxanes, common in hair products—linger in indoor air long after use. In just one hair care session, a person could inhale up to 17 milligrams of these chemicals.
Source: SciTechDaily