Highly fluorinated substances
Highly fluorinated substances, also known as PFAS, can be found in impregnated textiles, impregnated paper, detergents and fire-fighting foam. These substances are also found in products used in the engineering and electronics industries. Highly fluorinated substances are used because they have the ability to form smooth, water, grease and dirt-repellent surfaces. They are used in low concentrations in many products.
Areas of use
Textile and leather impregnation
Textile and leather impregnation is one of the largest areas of use for highly fluorinated substances. So-called fluorotelomers are used as a dirt and water-repellent surface on textiles, for example on all-weather clothing, tents, shoes, carpeting, upholstered furniture, awnings, etc.
Paper and food packaging
Paper can be treated with impregnating agent. It is mainly food packaging, where grease-repellent properties are desirable, that impregnating agents are found.
Highly fluorinated substances are also used in low concentrations in detergents such as window cleaners, floor polish, waxes and car care products. Although the concentrations in the products are low, emissions to the environment can be significant.
PFAS can also be used in paints, inks, varnishes and cookware (non-stick frying pans made with the fluoropolymer PTFE). Another example where highly fluorinated substances are used is ski wax. Ski wax is often marketed as containing fluorocarbons or PFC, which is another name for PFAS.
Perfluorooctanoic acid (PFOA) is sometimes referred to in the media as the “Teflon chemical”. PFOA is widely used as an auxiliary chemical in the production of the polymer polytetrafluoroethylene (PTFE). Teflon is a registered trademark and a brand. According to the manufacturer, PFOA is no longer present in the finished product, but production has historically been a source of large emissions to the environment.
There are different types of firefighting foams used for different types of fires. The so-called Class B foam may contain highly fluorinated substances. They are mainly used because of their superior ability to create a thin aqueous film between the foam and the burning fuel. The aqueous (watery) film allows the foam to spread quickly over the liquid surface while preventing evaporation and thermal (heat) radiation. These fire foams are used for petroleum fires at, for example, airports and oil refineries, but are also used in hand-held fire extinguishers that are marked as B extinguishers.
Disperse and persist in the environment
Highly fluorinated substances are a group of very stable substances. Some break down very slowly or not at all in nature, while others are converted into what are called persistent substances. Many of them are bioaccumulative, i.e. they accumulate in living organisms. Because highly fluorinated substances are fat and water repellent, they are not stored in fatty tissue like other bioaccumulative substances. They bind to proteins and are stored in other organs in the body, such as the liver and blood.
Some types of highly fluorinated substances are found in relatively high levels in animals, such as polar bears in the Arctic. These substances are also found in human blood, even in newborns.
PFOS (perfluorooctane sulfonate) is a so-called PBT substance, i.e. persistent, bioaccumulative and toxic. This means that PFOS is not broken down in nature, but accumulates there, is chronically toxic, disruptive to reproduction and toxic to aquatic organisms.
PFOS has now been replaced by other persistent highly fluorinated substances that are not absorbed to the same extent in living organisms and are therefore less toxic. The use of substances that can be degraded to PFOS has decreased in recent years. Our experience, however, is that they have largely been replaced by other highly fluorinated substances. Some of these, such as fluorotelomers, can slowly degrade to PFOA.
PFOA (perfluorooctanoic acid) is also considered almost non-biodegradable in nature, is disruptive to reproduction and is suspected to be carcinogenic in humans.