A group of more than 4,000 chemicals, PFAS have also been found in drinking water, electronics and furniture

Why you need to know about PFAS, the chemicals in pizza boxes and rainwear

What are PFAS?

PFAS, short for perfluoroalkyl and polyfluoroalkyl substances, are a group of at least 4,700 synthetic chemicals that have been in commercial production since the 1940s to make surfaces resist stains, water and grease.

The most widely studied are PFOA (also known as C8) – used for decades to make Teflon non-stick – and PFOS, used to make Scotchgard water repellent.

They don’t break down. PFAS are highly persistent and accumulate over time in humans, animals and the environment.

They can also be dispersed through air and water and have been found in the environment of the Arctic (and its polar bears) and open ocean waters.

What can PFAS be found in?

It can be found in non-stick cookware, fire retardants , stain and water repellents, some furniture, waterproof clothes, pizza boxes and take-out containers, food packaging, carpets and textiles, rubbers and plastics, electronics and some dental floss.

People around the world. The Centers for Disease Control and Prevention (CDC) found PFOA in in the blood of 98% of Americans, as well as in breast milk and umbilical cord blood.

The drinking water of about 16 million Americans, including 126 military bases, where PFAS-rich firefighting foam is used for training exercises. PFAS have also been found in fish, shellfish, vegetables and other grown in contaminated soil or water. The Environmental Working Group health advocates have created a US map of detections of PFAS in water.

Can PFAS cause harm?

Health effects of the various kinds of PFAS are debated, but a growing body of evidence has linked exposure to some of them to:

Developmental issues , cancer, liver damage, immune system disruption, resistance to vaccines, thyroid disease, impaired fertility and high cholesterol. PFAS have been dubbed “possibly carcinogenic” to humans by the Environmental Protection Agency (EPA) and the International Agency for Cancer Research (IARC).

A study funded by DuPont as part of a legal settlement with residents living near one of its Teflon facilities found that PFOA was probably linked to six disease outcomes: kidney cancer, testicular cancer, thyroid disease, ulcerative colitis, high cholesterol and pregnancy-induced hypertension.

Numerous studies on PFOS and PFOA on both humans and animals have shown a wide range of possible health effects, including decreased fertility among women, decreased sperm count and penis size, lowered birth weight, cancer and – among animals studied – death.

How can consumers limit any risks?

Exposure to PFAS comes mainly from drinking contaminated water , eating food packaged in certain materials, or using products embedded with PFAS.

Avoid non-stick cookware, Gore-Tex fabric and clothing made with pre-2000 Scotchguard, and personal care products containing PTFE or flouro ingredients. When in doubt, ask manufacturers if their products contain PFAS since they may not be labeled.

Ask your local health department if your water is contaminated above EPA-specified levels, and stop using it if so.

Watch out for local fish advisories and don’t eat contaminated catches.

How are PFAS regulated?

The federal government does not regulate PFAS.

Amid growing public concern, the EPA announced in February it would begin the process of regulating PFOA and PFAS in the next two years (these regulations, if issued, would not apply to other PFAS chemicals).

Some states with high exposure, including Washington, are pushing their own regulations and bans.

PFOS and PFOA have been largely phased out of use in the US under a 2006 voluntary agreement brokered by the EPA with eight major companies, including DuPont. However, these substances are still circulating in the country via imports. Research on the chemicals used to replace PFOA – including GenX, which is produced by DuPont spinoff Chemours – is limited. A 2018 draft assessment by the EPA noted animal studies showing effects on the kidneys, liver, immune system and more from GenX. Chemours is currently under legal pressure for alleged GenX contamination around its North Carolina facility, and is currently under a state consent order that includes a $12m fine and requirements to accelerate clean-up efforts. Chemours website says GenX technology “reduces the potential for environmental release and exposure … extremely low or no extractable water-soluble residuals in finished polymers and end-use articles”.

In the EU, where PFAS use and manufacture is much lower than the US, PFOS is regulated as a persistent organic pollutant, and more regulations are expected to kick in next year.

Canada has declared PFOS a toxic substance and prohibited its use and import.