Non-polymer PFAS can build up in blood protein of animals, and is not always removed quickly. This means that predators eating PFAS-contaminated food will have higher levels in their bloodstream, and concentrations can increase up the food chain. Studies suggest that build up of PFAS is similar to those of other Persistent Organic Pollutants such as DDT.PFAS are estimated to be settling in arctic regions at rates of tens to hundreds of kilograms per year (25-850kg per year), depending on the specific PFAS chemical in question. Certain PFAS are released as gases to the environment and are blown a long way by wind and air currents in the atmosphere,. These gas PFAS will over time degrade to more persistent chemicals like PFOS and PFOA. This may be one reason why PFAS of environmental concern have been found in remote regions such as the Arctic as well as near PFAS production sitesPFAS including PFOS and PFOA have been found in air samples around Europe. The chemicals are found in small quantities, but appear in almost all samples tested. PFAS enters the atmosphere both from factories and the air inside our homes. PFAS is found in treated waste water from industrial and domestic sources and has been found in both rivers and groundwater. Conventional drinking water processes will not remove PFAS.PFAS-coated clothes that are thrown away will often end up either incinerated or in landfill. Unless incinerated at very high temperatures (>1000oC), fluorinated polymers could release more harmful PFAS during burning. PFAS of environmental concern have also been found in landfill leachate. Non-polymer PFAS are used in the production of fluorinated polymers. The manufacture of stain-resistant finishes generally releases these PFASs into the environment, both by air and water emissions. They are very hard to remove during water treatment. Workers in textiles factories are some of the population most exposed to these potentially harmful chemicals. Small quantities of PFAS will be removed during wash and wear of products containing PFAS. This includes fluorinated polymers used on stain-resistant coatings, and non-polymers that remain on clothes after production (Lassen et al. 2015).Most UK waste still ends up in landfill, and this includes PFAS-containing products. Studies have shown that the liquid coming from landfills (known as leachate) often contain non-polymer PFAS chemicals. In the USA the total quantities were estimated at 563-638 kg in 2013. To properly break down PFAS chemicals high temperature (1000oC or more) incineration is recommended. Incineration of municipal waste does not necessarily reach these temperatures (min temp. required is 850oC), and the incomplete breakdown could release non-polymer PFAS.Wash and wear of clothing that contains PFAS-based stain-resistant or water repellent finishes release PFAS to the environment. Coatings are thought to lose effectiveness after 20-30 washes. This can include non-polymer PFAS, remnant from production or as a break-down product of side-chain polymers (Lassen et al. 2015). The manufacture of stain-resistant finishes releases PFASs into the environment, both by air and water emissions. PFAS are very hard to remove during water treatment. Industrial emissions are estimated to be the biggest source of these chemicals to the environment.

Frequently Asked Questions

What is stain resistance?

Lots of textiles, such as furniture, carpets and clothing, claim to be stain resistant. This often means that chemicals have been applied to the material to make the fabric repel water and oil. The term ‘stain resistant’ only implies that stains cannot penetrate the fabric as easily so that some stains wipe off. However, the flip-side is that if stains do get onto the fabric water cannot penetrate as easily during washing and the stain is harder to get out. Some brands also add a ‘stain release’ formula to allow stains out again but this is often not the case.

What chemicals are used to make water- and stain-resistant coatings?

Water and oil resistant finishes which are applied to materials can be made up of a number of chemicals. Many of these finishes contain PFASs (Per- or poly-fluorinated alkyl substances).  PFASs are synthetic chemicals of environmental concern, used in a wide range of products. Whilst there are not many alternatives to PFAS that work in the same way, some products, like school uniforms for example, are being produced and sold without using chemicals at all. Other products, such as some outdoor wear, are using innovative textiles and techniques for an efficient water-proof finish.

Are PFAS stain resistant coatings harmful to those wearing the products?

Most PFAS coatings on textiles are unlikely to cause harm, as they are made of large polymer molecules that cannot be easily absorbed by the human body.

The greater concern comes from the production of these chemical coatings, where PFAS of concern are released into the environment and they can build up over time as they don’t break down easily. As a result, there is strong evidence that the production  phase is a significant point of PFAS getting into the drinking water of towns and cities all around the world, as well as the wider ecosystems.

Are PFAS coatings bad for the environment?

Throughout the life-cycle of these chemicals, PFAS can leak out in production, wash and wear off  and leach from landfill and incinerators. At every point, there is a chance that PFAS will end up in our environment.

PFAS are used in so many everyday products, such as food packaging, on textiles, cosmetics, non-stick cookware and cleaning products, to name just a few. And as we know that PFAS last a long time, we understand that the PFAS found in our homes, workplaces, drinking water, wildlife and bodies1 are here to stay. We know these chemicals can do harm to animals from laboratory experiments, and there are signs they are harming wildlife, including polar bears.

How long does PFAS stain resistance last?

Fidra have only tested coatings on school uniforms. We found that the majority of PFAS-based stain resistant finishes on uniforms were only guaranteed to last 10 or 20 washes, depending on the brand used. Based on average washing habits this represents around a third of a school year.

Fidra also found that there was no evidence that the people who bought stain resistant uniforms washed them less or replaced uniforms less frequently, proving that stain resistant coatings didn’t reduce washing or increase the life of a garmet in real terms.

What can we do?

Avoiding PFAS-based products is becoming much easier. Many major brands and retailers have already switched to, or offer, PFAS-free alternatives for products like school uniforms and outdoor clothing, as well as kitchen wear and ski waxes. Fidra are still looking to understand the details of the chemistry used in these alternatives but feel reassured by some of the progress being made in this area.