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.

Where and why are PFAS used?

The widespread use and success of PFAS comes down to a few key characteristics that the majority of PFAS chemicals have. Understanding these will help you to start recognising where they might be found in the 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. 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 products either water- and oil-proof and means you can get water- and stain-resistant items, like clothing, whilst still keeping the garment light and breathable.

Have a look at your waterproof coat. Does it look fully sealed with a finish, such as wax, or is it waterproof and breathable?

PFAS chemicals can act as ‘surfactants’. Surfactants are used to help liquids mix efficiently, keep liquids that would set once applied in liquid form, and improve spreading, levelling and foam control. For example, surfactants help keep paints, waxes and polishes as liquids until they are applied to a surface. They also help the substance to be applied smoothly and easily, and are used in industrial cleaning products as they do not leave a residue.

PFAS chemicals are used a lot in firefighting foams due to the chemicals’ effectiveness of forming a film on top of a fire, stifling it quickly. Once firefighting foams have been used, it is highly likely that the foam will drain into water sources, polluting local environments, such as rivers, and even finding their way out to sea.

When suggesting non-PFAS alternatives in this case, Fidra recognise that it is extremely important to ensure there no loss of function.

Finally, PFASs are chemically very stable, which means they are hard to break down or change, even at extremely high temperatures. Environmentally, this causes significant problems (see Environment and Health). However it also makes PFASs commercially useful as it can be used to make products, like cook-wear, ‘slippery’.

Even at high temperatures our food, for instance a frying egg, won’t chemically interfere with the PFAS structure. Therefore, 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.