Forever Chemicals, in Plain Words

The basics

What PFAS are

PFAS are a family of thousands of man-made chemicals. They make pans non-stick, jackets waterproof and food wrappers grease-proof. They are also used in firefighting foam, cosmetics and many factory processes.

People call them forever chemicals because they hardly break down, not in nature and not in the body. The most common ones take years to leave your body. Over time they build up in soil, water, animals and people.

The Dutch news

What the tap water data showed

On 22 September 2026, Greenpeace Netherlands published an analysis of PFAS figures from the Dutch water companies. It found that the tap water of more than a third of the Dutch population is above the advice value set by RIVM, the national health institute. The water in Zaanstad was the highest in the country, at more than three times that value.

So is the water safe? It meets the law. The Dutch advice value is simply much stricter, because it is based on newer research about the immune system. RIVM, the Dutch water companies and Greenpeace all say: keep drinking tap water.

The part most headlines left out

Most PFAS comes from food

According to RIVM, people in the Netherlands take in about three times as much PFAS through food as through drinking water. That makes tap water only about a quarter of the total.

Europe's food safety agency (EFSA) names fish, fruit and eggs among the foods that add the most. PFAS reach food through polluted soil and water, animal feed, and packaging. Since 12 August 2026, the EU bans PFAS in food packaging.

What the science says

Why scientists are concerned

In 2020, EFSA set a safe weekly amount for the four most common PFAS: 4.4 nanograms per kilogram of body weight per week. It found that part of the European population already takes in more than that.

Its main concern is the immune system: children with more PFAS in their body respond less well to vaccines. Toddlers and other children are the most exposed group, and a baby can take in PFAS during pregnancy and breastfeeding.

What you can do

Calm, practical steps

1. Keep drinking tap waterThis is the advice of RIVM, the water companies and Greenpeace. Tap water is only about a quarter of what you take in.
2. Look up your own areaWater companies publish their PFAS figures. Search for your water company's name and "PFAS".
3. Eat a varied dietMost PFAS comes from food, so variety helps. Follow your country's advice on how often to eat fish.
4. Thinking about a water filter?Filters vary a lot. Before you buy one, check for independent test results that show it removes PFAS. We will cover this in a later guide.
5. Want to know what is in you?That is the next post in this series: how testing for PFAS actually works.