Recent research found that common heat-styling hair care products emitted trillions of nanoparticles into the air. A 2022 study by a team including Nusrat Jung of Purdue University and others cautions that such particles may collect in the lungs. Using advanced technology, the team measured airborne nanoparticles in real time, highlighting the significant health implications of everyday hair care routines.
Fischer and Burchfield carried out their experiments in a tiny house custom-made for their research. This new space is known as the Purdue Zero Energy Design Guidance for Engineers (zEDGE). This controlled environment is what allowed the team to first observe how heat applications from styling tools lead to atmospheric nanoparticle emissions. This small study highlights the need for more robust indoor air quality investigations, especially while hair is being styled.
In Jung’s laboratory, a state-of-the-art high-resolution electrical low-pressure impactor (HR-ELPI+) was used to capture and analyze nanoparticles. This innovative approach provided researchers with a more robust understanding of how emissions occur during personal care activities.
The Role of Heat in Nanoparticle Emission
At quite the serendipitous moment, the research team stumbled upon an exhilarating find. They experienced that warmth was a major component in producing hair care products airborne nanoparticles. When heated, these products release toxic and hazardous volatile chemicals. This process results in pulses of nanoparticles, with recent measurements showing production of 10,000 to 100,000 nanoparticles per cubic centimeter.
“Heat is the key force leading to this process,” said Jianghui Liu, a member of Jung’s research team. Cyclic siloxanes and other low-volatility ingredients volatilize, nucleate and grow into new nanoparticles—most of them still smaller than 100 nanometers. Since combined heating effectively increases product efficiency, this surprising discovery means heat can enhance hair care regimen. It also greatly increases the likelihood of releasing harmful particles into the environment.
The research specifically focused on D5 siloxane, an organosilicon compound. One ingredient in particular that usually ranks at the top of the lists for myriad hair care products. In her comment, Liu stated her worry over these formulations. He explained what those risks can be, especially for heat resistant products such as hair sprays, creams, and gels.
Health Implications of Nanoparticle Exposure
Beyond air quality, the implications of this research are damning on respiratory health. The modeling conducted by Jung’s team indicated that more than 10 billion nanoparticles could deposit in an individual’s respiratory system during a single hair styling session. The greatest concentration is in the pulmonary region, the furthest portion of the lungs down.
Jung emphasized the significance of their findings: “By providing a detailed characterization of indoor nanoparticle emissions during these personal care routines, our research lays the groundwork for future investigations into their impact on indoor atmospheric chemistry and inhalation toxicity.”
Liu continued to emphasize the hazards of long-term exposure to these nanoparticles, particularly in enclosed areas with poor ventilation. “If you need to use hair care products, minimize their use and make sure the area is well ventilated,” he counseled.
Recommendations for Reducing Exposure
As a way to limit exposure to the airborne nanoparticles created by hair and beauty care products, Jung recommends a few strategies. These recommendations are based on those new findings. One of the simplest, most effective ways is to run bathroom exhaust fans while styling hair to help ventilate the space. Making sure the space is adequately ventilated can cut the amount of these toxic airborne particles in half.
Jung and Liu recommend ditching the heat-styling devices whenever you can. By addressing these research gaps, future research will further our understanding of emissions and exposures associated with heat-based hair styling. This information will improve indoor air quality intervention risk assessments and help deploy more effective mitigation strategies.
Since we first modeled hair care product emissions during heat wave scenarios, we focused in on the volatile chemicals emitted. Those were really scary results to begin with,” Jung said. Although we knew that the airborne hazards of these products—especially ‘leave-on’ formulations—are substantial, now it turns out that they may be worse than we thought.