What are PFAS used for?
Per- and polyfluoroalkyl substances, or PFAS, are a group of chemicals that have been used in manufacturing and added to consumer products since the 1950s. They slide grease and dirt from carpets and textiles, protect industrial equipment from heat and corrosion damage, and help smooth and condition skin.
They are also used in jet engines, medical devices, refrigeration systems, the construction industry and electrical appliances.
However, they can take hundreds or even thousands of years to break down after the products in which they are used are discarded. This means that if they leak into the ground or water, which often happens, they can remain there for centuries.
They can also move, meaning you don’t have to live near a chemical plant or landfill to be exposed to them. And they can accumulate over time in the tissues of living things, including humans. This is concerning because at least some PFAS have been linked to health problems such as high cholesterol, reduced immunity and several forms of cancer.
However, there are thousands of these chemicals, and while the toxicity of some of them has been clearly established, others are potentially less toxic, or have not been studied, so we don’t know if they are harmful.
Do we really need them?
There are often alternatives. For example, consumer products such as frying pans or school uniforms do not require a non-stick or stain-resistant coating to be effective. Cast iron or stainless steel pans also work, while a wet sponge will remove most stains quickly.
Manufacturers can also develop chemical substitutes, such as PFAS-free firefighting foam now used at many commercial airports, including London’s Heathrow. However, making them takes time, and there are some chemicals with important industrial applications for which no alternatives currently exist.
A too quick switch to alternatives could also cause further problems. “There are some things we still need to make water or stain resistant, and if we ban PFAS too quickly, there’s a chance we’ll end up using another product that is also persistent and bioaccumulative,” said Stephanie Metzger, a policy advisor sustainable chemicals at the British Royal Society of Chemistry. “We need investment and research into alternatives that are both effective and proven to be better for us.”
What are the most important ones to pay attention to?
There are three main types of forever chemicals: fluorosurfactants – soap-like molecules commonly used in industry and also added to some paints, varnishes and firefighting foams; fluoropolymers – long, plastic-like chains of carbon and fluorine with a variety of consumer applications (the best known is the nonstick chemical Teflon); and fluorocarbons – gases or liquids with small molecules, used in refrigerators and air conditioning systems.
Fluoropolymers and fluorocarbons have not been proven to cause direct harm to consumers, but they can cause problems once their lifespan ends and they begin to break down into other PFAS.
The most notorious fluorosurfactants are perfluorooctane sulfonate (PFOS) and perfluorooctanoic acid (PFOA). When news articles talk about the toxicity of PFAS, they often refer to these substances because there is compelling evidence that they are harmful. A studywhich included data from approximately 69,000 people, concluded that there is a likely link between PFOA exposure and diagnosed high cholesterol, chronic kidney disease, liver disease, ulcerative colitis, thyroid disease, testicular and kidney cancer, and pregnancy-induced hypertension (high blood pressure). Busy).
For this reason, the use of PFOA and PFOS is banned or severely restricted under a global treaty called the Stockholm Convention. However, this has led to its replacement with various chemicals, some of which can also be harmful.
Should I be concerned about exposure to everyday objects?
PFAS are everywhere, from rainwater and Arctic ice to the sewage sludge farmers spread on their fields. They have also been found in the blood of up to 99% of Americans. While many scientists are concerned about these chemicals, they emphasize that the immediate risk from many of the PFAS-containing products in our homes is likely low.
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“The biggest risk doesn’t come from household products,” says Metzger. “The greater potential route for harm is drinking contaminated water and possibly through food; there are movements to phase out the use of PFAS in food packaging because it comes into contact with what we eat. It is a more direct link with our body than, for example, a carpet that has been treated to resist stains.”
The environmental organization Fidra found PFAS the packaging of foodstuffs collected from eight of the nine major UK supermarkets and 100% of the takeaways it tested – with significant amounts detected in biscuit and bakery bags, microwave popcorn packaging, pizza boxes, takeaway food and compostable molded fiber takeaway boxes.
In theory, PFAS can also enter your body through cosmetics or personal care products, especially products applied to the eyes or lips.
Despite these concerns, the strongest predictor of having high levels of PFAS in your body appears to be living in an area with a heavily contaminated water supply. PFAS can enter drinking water through discharges from factories, the use of certain firefighting foams at, for example, airports or military bases near water sources, or runoff from landfills. Last year the Guardian reported on the legal discharge of large quantities of PFAS into the River Wyre by a chemical factory in Lancashire.
Since July 2022, the Drinking water inspection (DWI), which oversees the safe drinking water supply in England and Wales, has required water companies to monitor the levels of 47 individual PFAS in drinking water and notify consumers if they exceed certain levels. If they do, they must also treat the water – for example by diluting it with water from other sources.
Some scientists and campaigners would like to see the introduction of stricter limits. The Royal Society of Chemistry has proposed a maximum acceptable concentration of 10 ng/l (0.01 micrograms per liter) for individual PFAS – 10 times lower than current guidelines.
Research is also urgently needed into new ways to remove PFAS from the environment and break them down into harmless molecules.
Can we rid our lives of PFAS?
As tempting as it may be to rid your home of all PFAS-containing items and take them to the landfill, experts agree that this is probably the worst thing you can do from an environmental perspective.
Metzger recommends considering the life cycle of the products we buy: “Your nonstick pan may not hurt you today, as long as you use it properly. But if it ends up in a landfill and contaminates the environment, the PFAS can persist in it for decades or hundreds of years, contaminating the soil and water systems for you and your children or grandchildren.”
