Proper Ventilation Could Avert Harm From Hair Care Products

A recent Purdue University research has shown that several chemicals — most notably a group called cyclic volatile methyl siloxanes (cVMS) — that are commonly found in everyday hair care products easily evaporate and linger in the air after they’re applied.

To this end, an expert has recommended using proper ventilation when applying hair care products and using hot tools.

Results of the findings are published in ‘Environmental Science & Technology’. The researchers discovered that an average hairstyling session at home could result in someone inhaling between one and 17 milligrams of these chemicals, which researchers said are potentially hazardous to health.

The researchers also learned that using a curling iron or a flat iron and applying high heat to hair that has been treated with these products can intensify the release of these chemicals. So what do these findings mean for the millions of people who regularly use hair care products and hot styling tools?

While previous environmental studies have focused on the siloxanes found in wash-off personal care products like shampoo and shower gel — meaning they’re rinsed off after applying — the researchers wanted to analyse these chemicals with respect to leave-in hair products, including hair gels, oils, creams, waxes and sprays.

Researchers gathered volunteers between the ages of 18 and 65 who regularly use leave-in hair care products, and instructed them to perform their typical styling routine in the university’s lab.

“It’s a protected environment with a very controlled atmosphere where we can detect the composition of the air every fraction of a second,” said lead author of the study Nusrat Jung, assistant professor at the Lyles School of Civil Engineering at Purdue University. Before, during and after hairstyling, Jung and her colleagues measured real-time emissions of volatile organic compounds (VOCs), which included siloxanes.

They found that the most abundant chemical that lingered in the air was decamethylcyclopentasiloxane, otherwise known as D5 siloxane (or cyclopentasiloxane) — an ingredient used in most hair care products for its ability to make hair smooth and shiny.

“A styling routine that mixed these chemicals with a heated appliance further exacerbated the release of this product into the air,” said Jung. When the study participants used a hot styling tool that reached 210 degrees Celsius/410 degrees Fahrenheit, the chemical emissions from the hair care products increased anywhere from 50 per cent to 310 percent.

“I was extremely surprised to see such significant emissions of volatile chemical mixtures coming from off-the-shelf hair care products,” said Jung, who has been using these items to style her own curly hair. “If I go to a salon for a hair treatment, for example, I’m expecting to be exposed to chemicals.

But I really did not expect that this would happen if we were to replicate our everyday hair care routine.” It’s important to point out that there is minimal science on whether D5 siloxane poses any health risks to humans — most of the research on its potentially harmful effects are on animals.

The Environmental Working Group scores cyclopentasiloxane as a three out of 10 on its toxicity scale, with 10 being the worst. However, Jung explained that D5 has already been classified as “very persistent and very bioaccumulative” — meaning, the substance doesn’t break down easily in the environment and can gradually build up in humans and animals — by the European Chemicals Agency.

So it’s unclear whether that might be harmful with frequent use over time. “When you’re taking a shower with wash-off products, this water is getting treated and going somewhere, which is why it was detected in small animals and marine animals,” she said.

In 2015, a study conducted in the Netherlands showed that inhaling D5 siloxane from personal care products can lead to adverse effects on the respiratory tract, liver and nervous system of laboratory animals. Jung also notes that “the whole continent [of Europe] has restricted this chemical formulation.”