Leaving a trace

PFAS can repel water, oil, sweat, dirt and heat, making them ideal for outdoor gear. But what about the impacts of these 'forever chemicals' on the environment and human health?

- Sam Pyrah investigates

Leave no trace: it's a maxim familiar to anyone who enjoys exploring the countryside. But the kit we wear and carry in the great outdoors often does leave a trace - of 'forever chemicals'. Or, to give them their correct name, per- and polyfluoroalkyl substances (PFAS; the term PFC, referring to a related type of compounds, is also commonly used).

The first PFAS were developed in the 1930s – PTFE, trademarked as Teflon, was discovered in 1938 – and have since been used in countless consumer goods, from nonstick pans to lipstick, upholstered furniture, food packaging, clothing and cleaning products.

“The reason they feature so heavily in outdoor apparel and kit is because of their remarkable capacity to repel water, oil, sweat, dirt and heat – and their durability,” says Charles Ross, lecturer in performance sportswear design at the Royal College of Art and a textiles consultant. You’ll find them in everything from waterproof jackets to hiking boots, tents, rucksacks and sleeping bags. They’re used in surf wax and bike lube – even products that you apply directly to your skin, such as some sunscreens.

With such widespread use, you might assume that this family of chemicals – which now numbers many thousands – has been rigorously tested and deemed safe. Not so. Their harmful effects on the environment, wildlife and human health are increasingly being recognised. Last year, 59 of the world’s leading scientists wrote to the UK government urging action on regulating PFAS. Studies have linked PFAS contamination with an increased risk of some cancers, reproductive issues (including decreased fertility, pregnancy complications and low birth weight), and disruption to hormonal and immune systems.

“One of the leading concerns about PFAS is their extreme persistence,” says Hannah Evans, project lead on PFAS at Fidra, a Scotland-based environmental charity supporting sustainability and preventing pollution.