PFAS in drinking water: What you need to know

What PFAS are and why they don’t break down

PFAS stands for per- and polyfluoroalkyl substances. This term covers over 10,000 different chemical compounds that all have one thing in common: an extremely stable bond between carbon and fluorine. It is precisely this stability that makes them so useful to industry and so problematic for the environment.

PFAS have been used in countless products since the 1950s. Non-stick coatings in frying pans, water- and grease-repellent textiles, food packaging, cosmetics and fire-fighting foams are just a few examples. The chemicals fulfil their purpose excellently in these applications. However, once they enter the environment, they remain there. They do not break down through sunlight, bacteria or natural chemical processes. The term ‘forever chemicals’ is therefore no exaggeration.

The problem: PFAS accumulate in the soil, in groundwater and ultimately in the human body. Studies show that virtually everyone in Europe has measurable concentrations of PFAS in their blood.

How PFAS enter drinking water

The most common route is via groundwater. Firefighting foams containing PFAS have been used at airports and military sites for decades. These chemicals seeped into the ground and reached the groundwater. In the border region near Basel (Saint-Louis), one such case led to pregnant women and infants under two years of age being advised against drinking tap water. 60,000 people in eleven municipalities were affected.

But firefighting foams are only part of the problem. Industrial wastewater, landfill sites and sewage treatment plants also contribute to the contamination. Sewage treatment plants are not designed to remove PFAS. Whatever ends up in the drain – whether from washing textiles, cosmetics or cleaning products – ultimately flows into rivers and, from there, partly back into the groundwater.

The figures for Switzerland are sobering: as part of the NAQUA programme, the Federal Office for the Environment (FOEN) has found that around half of all groundwater monitoring points show evidence of PFAS. In urban areas, over 90% of monitoring points are affected. PFAS are also regularly found in groundwater in Germany and Austria. Across Europe, a research consortium has identified over 23,000 contaminated sites, around 2,300 of which are classified as high-risk sites.

What PFAS can do to the body

The health risks are now well documented. Four areas are particularly affected.

The immune system is sensitive to PFAS exposure. Studies show that certain PFAS impair the body’s ability to respond to infections and vaccinations. This effect is particularly measurable in children.

The thyroid gland is also affected. PFAS can alter hormone balance by accelerating the breakdown of thyroid hormones. Recent research also suggests a link to an increased risk of thyroid cancer.

The liver is the organ in which long-chain PFAS tend to accumulate. Proven effects range from fatty liver to cell damage.

Furthermore, PFAS are associated with an increased risk of kidney and testicular cancer. The International Agency for Research on Cancer (IARC) has classified PFOA as possibly carcinogenic. Effects on metabolism and child development are also being investigated.

New limit values from 2026 and 2028

For a long time, there were no binding limit values for PFAS in drinking water. That is now changing. The EU Drinking Water Directive of 2020 is being gradually transposed into national law.

In Germany, binding limit values have applied for the first time since January 2026: 0.1 micrograms per litre for the sum of 20 defined PFAS substances. From January 2028, an even stricter limit will be introduced: 0.02 micrograms per litre for the four most critical individual substances – PFOA, PFOS, PFHxS and PFNA. Water suppliers must carry out regular testing and inform the public if limits are exceeded.

Austria has also adopted the EU limits. Water suppliers with a supply volume exceeding ten cubic metres per day are obliged to carry out monitoring.

Switzerland has postponed the adoption of the stricter EU limits for the time being. The limits currently in force (0.3 micrograms per litre for PFOS, 0.5 micrograms per litre for PFOA) are therefore significantly less stringent than the new EU requirements. The Federal Council is working on an action plan against persistent chemicals, but a concrete timetable has yet to be established.

Why boiling doesn’t help

A question many people ask: Can I remove PFAS by boiling the water? The answer is clear: No. PFAS are extremely heat-stable. It is precisely this property that makes them so useful in non-stick pans. When boiling, the water evaporates, leaving the PFAS behind. This actually increases the concentration in the remaining water.

Even standard ion-exchange jug filters, which primarily reduce limescale and chlorine, are not designed for PFAS. Anyone wishing to effectively remove PFAS from their drinking water needs a filter system that has been tested and certified for this purpose.

Which filters can remove PFAS

Three filter technologies have proven effective against PFAS. Each works differently, and each has its own strengths and limitations.

Activated carbon filters bind PFAS through adsorption on their porous surface. A prerequisite is that the activated carbon is used as a compressed block, not as loose granules. Effectiveness varies depending on the type of PFAS: long-chain compounds are retained more effectively than short-chain ones. Regular cartridge changes are important, as filter performance declines over time.

Reverse osmosis systems force water through an extremely fine membrane and achieve removal rates of over 94%. However, they require electricity, produce wastewater and, in addition to PFAS, also remove natural minerals from the water.

Multi-stage filter systems using mineral ceramics and activated carbon combine several filtration principles in a single pass. The water passes through various layers of natural ceramics and activated carbon, with the extended contact time enabling thorough adsorption. Effectiveness depends on the composition and number of filter layers. Well-designed systems, whose PFAS performance has been verified in the laboratory, can match the other methods. Their advantage: minerals are retained, and the system operates without electricity and without producing wastewater.

The key point for all three technologies is this: request a laboratory test report from an accredited institute that provides concrete evidence of the PFAS filtration performance. Not every filter that reduces pollutants is automatically effective against PFAS.

Our approach at MAUNAWAI

We have had our filter systems specifically tested for PFAS. The result: in a test report from the Potsdam Water and Environment Laboratory (PWU, DAkkS-accredited), all ten PFAS substances tested were reduced below the detection limit following filtration. These included the four particularly critical compounds PFOA, PFOS, PFHxS and PFNA, which will be subject to the strictest EU limits from 2028. The reduction was over 99.99%.

This falls well below the stricter limit of 0.02 micrograms per litre, which will apply from 2028. We publish the full test results transparently under Science and Studies.

Our Pi technology works with 21 natural mineral ceramics in combination with activated carbon. Contaminants are bound, minerals are retained. No electricity, no chemicals, no waste water. Whether as a Kini filter jug, a PiPrime gravity filter or a Peka home filter: all systems use the same filter technology.

What you can do now

Find out about the water quality in your region. Many water suppliers publish their analysis results online. If you want to know whether your tap water contains PFAS, a professional water test can provide clarity.

And regardless of this: when choosing a water filter, make sure the manufacturer can substantiate the PFAS filtration performance with a laboratory test report. Not every filter that reduces pollutants is also effective against PFAS.

We would be happy to advise you personally. Contact us or discover an overview of all MAUNAWAI systems.