Hot styling with hair products can be detrimental to your health
Hair cosmetics often contain ingredients that are easily evaporated. During use, people inhale some of these chemicals, which can lead to health problems. Scientists have studied the emissions of these volatile organic compounds, including siloxanes, which give hair its shine and smoothness.
There is a huge range of hair care products on the market, with hundreds of varieties of shampoos, conditioners, sprays, creams, lotions, gels, oils and mousses. According to studies, between 16% and 70% of the population use indelible styling products. Most of them contain siloxanes (polyorganosiloxanes, silicones) - high molecular weight compounds, the main molecular chain of which is built of silicon and oxygen atoms, and the side organic groups contain carbon atoms bonded to a silicon atom. They have heat and frost resistance and are actively used in the production of cosmetics.
Researchers at the Lyles School of Civil Engineering (USA) recently discovered that some substances, particularly cyclic volatile siloxanes, linger in the air after use. The average person can inhale a cumulative mass of between one and 17 milligrams of potentially harmful substances per session. The results are published in the journal Environmental Science & Technology.
The scientists conducted 46 experiments over the course of two months. To do so, they created a tiny, ventilated house where participants used their regular hair products and styling appliances. Before, during and after the treatment, the scientists measured VOC emissions in real time. Mass spectrometry data showed rapid changes in the chemical composition of the air in the house. The majority came from cyclic volatile methylsiloxanes. Emissions were influenced by product type and hair length, as well as styling tool type and temperature. Longer hair and higher temperatures also contributed to higher emissions.
The researchers estimated that the potential daily inhalation of siloxane by those who use them in hair care could be as high as 20 milligrams per day. An exhaust fan removed most of the air pollutants from the room within 20 minutes of styling (not all styling rooms have forced exhaust ventilation, however). However, even in this case, it is difficult to speak about the complete safety of the practice: it can affect the quality of street air in densely populated cities.
The authors noted that siloxane is classified as "very persistent, with a high capacity for bioaccumulation." And while the results of tests on laboratory animals are already worrying, there is little information on its effects on humans.
"No detailed studies have been done on this, so we really have no idea what degree of threat these substances pose when inhaled over a long period of time. "Washable products such as shampoos have been studied, but there has been little or no testing with 'non-washable' products such as sprays and oils," the scientists reported.
They also found that applying high temperatures to these substances, such as with curling irons or straightening hair, contributed to additional release of substances into the air. The researchers found that when temperatures rose to plus 210 degrees Celsius, emissions of substances from hair care products increased between 50 percent and 310 percent.
"Siloxane is known to have adverse effects on the respiratory tract, liver and nervous system of laboratory animals. Because of this, the use of this substance in flushable cosmetic products has already been restricted in the European Union," the researchers concluded.