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.

Properties and Uses

The widespread use and success of PFASs comes down to a few key characteristics, understanding these will give you enough knowledge to start guessing where they might be found and looking out for them in products you buy.

Firstly, they have the ability to change the surface tension of liquids which come into contact with them. In practise this means they can control whether liquids ‘bead’ or ‘spread out’ when they hit a surface. This is much more useful than it might initially sound. When liquids bead, they run off more easily, they don’t sit on surfaces and they don’t absorb into them. This is key to making fabric waterproof without having to completely seal it, which in turn means you can get ‘water-resistant’ whilst still keeping the garment ‘breathable’.

When you see these terms together it’s highly likely PFASs are being used. Have a look at your nice new waterproof coat, does it look fully sealed with a finish such as wax or is it waterproof and breathable?

PFASs are also ‘hydrophobic’ and ‘lipophobic’ (hydro- meaning water, lipo- meaning fat, -phobic meaning fear or aversion), this simply means water and oil is repelled by them. This, along with the beading effect mentioned above, keeps fabrics water-resistant but additionally helps them to repel oil.

This stops a wide range of stains being able to get in to the fabric and textiles. So, if you see the term ‘stain-resistant’ being used, especially when the label specifies ‘oil-based’ stain (as this is a property hard to replicate with other chemistries) you are more than likely looking at something that use PFASs.

Examples include clothing, children’s school uniforms and stain resistant carpets.

This oil-repellent nature isn’t just useful for fabrics; it also helps to keep our cardboard and paper take-away containers intact when they come into contact with greasy pizzas and fast foods.

Grease-resistant food packaging and food contact materials such as pizza boxes, microwave popcorn bags and grease proof paper are all common examples of products that use PFASs.

Linked to the changes in water tension, PFASs can act as ‘surfactants’. Surfactants are used to help liquids mix efficiently, they help them to ‘wet’ hard surfaces that are otherwise difficult to wet, improve spreading, levelling and foam control. In practise this means they help paints, waxes and polishes go on smoothly and are used in industrial cleaning products.

By helping ‘wet’ hard surfaces they result in products that leave thinner films and less residues behind, for example in ‘streak free’ glass cleaners.

Another important use, and a key source of PFAS to the environment, is in fire-fighting foam. The ability to form a film on top of a fire means they are extremely effective for large scale industrial fires to be quenched quickly and efficiently. When suggesting non-PFAS alternatives in this case it is extremely important to ensure no loss of function.

Finally, PFASs are chemically very stable, they are hard to break down. Environmentally this causes significant problems (see Environment and Health), however it also makes PFASs commercially useful, it can be used to make products ‘slippery’. Even at high temperatures foreign substances, like a frying egg, don’t chemically interfere with the structure, they can’t get a hold. Hence PFASs are used to produce a particularly slippery type of plastic called PTFE (Teflon) and this is what is commonly used on cookware. If your cookware is non-stick, chances are it uses Teflon which is manufactured using PFASs.