Commonly used hair care products and styling techniques may release potentially harmful chemicals into the air, significantly affecting indoor air quality, warns a new study conducted by researchers in the USA. The study led by Nusrat Jung, Assistant Professor at Purdue University's School of Civil Engineering, involved 46 experiments carried out in a controlled environment that simulated a home. Participants aged between 18 and 65 repeated hair care routines using various products and styling tools while researchers measured air volatile organic compounds (VOCs) concentrations before, during, and after each experiment using advanced mass spectrometry.
Revelations from the Experiments
The researchers examined the relationship between styling tool temperatures, VOC emissions, ventilation conditions, and hair surface area. The experiments linked higher tool temperatures and greater hair surface area to increased VOC emissions. One particular VOC, decamethylcyclopentasiloxane (D5), contributed most to the emissions. D5 is popular in styling products due to its stability at high temperatures and smooth texture. However, it has been found to cause respiratory, liver, and nervous system issues in animals, leading the European Union to restrict its use in cosmetics.
Impacts on Human Health
The researchers underscore the necessity for more comprehensive human studies to understand the health impacts of these substances. Measurements showed that an individual could inhale up to 20 mg of D5 daily. Using a bathroom exhaust fan could reduce D5 exposure by over 90%. However, this solution increases environmental impacts, as cumulative D5 emissions from indoors to outdoors were higher in one hour with the fan than in three hours without it.
Implications for Indoor and Outdoor Air Quality
Assuming that 10% of hair care products are siloxane-based, the total D5 emission from indoors to outdoors could reach 0.4 to 6 tons annually in the USA. The researchers advise against using these products and stress the need for further study of the impacts on people and the planet, as well as regulatory measures. The study, published in the journal Environmental Science & Technology, shines a light on the potential health risks associated with common hair care routines and products, calling for more awareness and caution.