PFAS: What are forever chemicals used for and are they dangerous?

A pilot installation for effective PFAS purification (Belga Mag/AFP via Getty Images)
A pilot installation for effective PFAS purification (Belga Mag/AFP via Getty Images)

Experts are calling on stricter limits for PFAS, or forever chemicals, in UK drinking water supplies. The harmful chemicals, found in products and packaging, have earned their name as they are almost impossible to break down.

Research on PFAS has found that the chemicals can cause considerable harm to human health, with recent studies finding they even reduce women’s fertility.

The Royal Society of Chemistry is now calling on the UK government to take action by overhauling drinking water standards and tackling PFAS concerns.

While authorities maintain that UK drinking water is safe, current regulations allow for water to contain up to 100 nanograms of PFAS per litre before a water company has to take action.

A growing number of people are also taking matters into their own hands, investing in water filters that can help to remove PFAS chemicals from drinking water.

But what is PFAS and why are these chemicals dangerous?

What are PFAS?

PFAS, or per- and polyfluoroalkyl substances, are a group of about 10,000 chemicals that are resistant to oil and water.

They have been widely used since the 1940s, and are used in products like non-stick cookware and packaging. They’re also used to make stain-resistant fabric used in clothes and carpets.

They are very slow to break down, due to their strong carbon-fluorine bond, giving them the name “forever chemicals”.

Once PFAS chemicals enter the environment, through household drains or factories, they will linger and potentially make their way into drinking supplies and the food chain.

Some of these chemicals are thought to be highly toxic.

Why are forever chemicals harmful?

People can be exposed to PFAS from tap water or food, or by using products made of PFAS.

PFAS break down slowly, meaning the levels of PFAS in the blood can increase. If people consume more of the chemicals than they excrete, this could lead to bioaccumulation in their bodies, according to the National Institute of Environmental Health Sciences.

PFAS have been linked to higher risks of certain cancers among other health issues, however, more studies are needed.

Two types, PFOA and PFOS, have also been linked to serious health conditions affecting the stomach, liver and thyroid but their use is now restricted.

Earlier this year, the first study on the impact of PFAS on fertility found that women with higher levels of the chemicals in their blood had a 40 per cent lower chance of becoming pregnant within a year of trying to conceive, as reported by the Guardian.

Dr Nathan Cohen, lead author of the research at the Icahn School of Medicine at Mount Sinai in New York, said: “Our study strongly implies that women who are planning pregnancy should be aware of the harmful effects of PFAS and take precautions to avoid exposure to this class of chemicals.”

Research published in 2021 suggested that PFAS are widely present in English surface waters and groundwater.

It's not just humans that are at risk, either. Plants and wildlife are also believed to be negatively impacted by PFAS contamination.

In March, researchers found that England’s wild fish contain high levels of an industrial pollutant that if eaten more than twice a year would exceed recommended EU safety guidelines.

Which countries want to ban forever chemicals?

In January, five EU countries (Denmark, Germany, the Netherlands, Norway and Sweden) proposed banning 10,000 PFAS.

In March, the US proposed restrictions on chemicals in drinking water, which would require communities to test and treat water.

In April, the British government said it was considering banning their use in firefighting foam.