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Transforming PFAS-Contaminated Soil into Sustainable Bricks

In recent years, the pervasive threat of PFAS (per- and polyfluoroalkyl substances) pollution has captured global attention, igniting urgent discussions and actions aimed at tackling its far-reaching environmental and health consequences. PFAS, a class of synthetic chemicals known for their persistent and bioaccumulative nature, has permeated water supplies, contaminated soils, and generated a growing public health crisis. They are widely used in various everyday products like non-stick cookware, waterproof mascara, and even firefighting foam. Unfortunately, these chemicals are notorious for their persistence in the environment, earning them the nickname “forever chemicals.” They don’t break down naturally, leading to contamination of soils and waterways.

Addressing PFAS (per- and polyfluoroalkyl substances) pollution is of paramount importance due to its wide-reaching and severe consequences. PFAS contamination poses a direct threat to human health, as exposure can lead to a range of health problems, including cancer and developmental issues, and can contaminate drinking water sources. Furthermore, PFAS are persistent in the environment, making long-term remediation necessary. Their bioaccumulation in the food chain further perpetuates the risk to both humans and wildlife. There are ongoing efforts to regulate PFAS and develop remediation methods, but it’s a complex challenge due to their persistence and widespread presence.

Emy Bensdorp has made bricks from PFAS-contaminated clay soil. Top and above photo by Sem Langendijk

Emy Bensdorp’s Innovative Solution To Address PFAS Pollution

Emy Bensdorp, the founder of the startup Claybens, has demonstrated the ability to eliminate PFAS chemicals from contaminated clay soil by transforming it into bricks. Her solution involves taking PFAS-contaminated clay soil and converting it into bricks using a standard brick manufacturing process, where ceramics are heated to extremely high temperatures in a kiln, ranging from 900 to 1,200 degrees Celsius. This intense heat effectively breaks down and destroys the PFAS chemicals in the soil. Importantly, the final product is entirely free from any detectable trace of these harmful substances. While Bensdorp does not believe the process emits toxic fumes or particles, testing in this regard is still pending.

“The most interesting thing about these chemicals is that they’re actually great because they are water-resistant, fireproof, and long-lasting,” Bensdorp said. “But now we know that they last forever, which is less great. And they bioaccumulate as well,” she added.

A look back

In 2020, Bensdorp initiated a project with the method in response to a Dutch Council of State ruling that had halted the country’s building industry due to the revelation of PFAS contamination in up to 90% of Dutch soils. Particularly alarming were the high PFAS levels in specific hotspots, where factors such as industrial activities, improper waste management, or the use of firefighting foam had led to extensive contamination.

The firing process eradicates the chemicals

What sets the method apart?

What sets Bensdorp’s method apart is its innovative approach, relying on the extreme heat of kilns to trigger a chemical reaction that effectively breaks down the chains of fluorine atoms that make up PFAS. This project is grounded in academic research, which typically involves heating PFAS for a short time at temperatures of 1,000 to 1,400 degrees. In contrast, the brick manufacturing process involves heating the soil at a similar temperature for a longer duration, making it an effective method to rid the soil of these harmful chemicals.

Emy Bensdorp, the innovator behind this approach, noted, “It’s a significant problem, not only in the Netherlands but throughout Europe. Legislation is becoming increasingly stringent due to our growing understanding of the toxicity of these chemicals. However, until now, there was no viable solution for dealing with clay soil contaminated by PFAS.”

Scientific Method

Emy Bensdorp’s innovative method hinges on the science behind it. It relies on a process called defluorination, which is triggered by the intense heat of a kiln. This process effectively dismantles the chains of fluorine atoms that compose PFAS, rendering them harmless. What sets this approach apart is its seamless integration into the existing brick manufacturing process, requiring minimal adjustments to infrastructure.

The bricks are made through standard manufacturing processes

How Does the Method Work? 

1. Soil Collection: The initial step involves gathering clay soil contaminated with PFAS. Such soil is typically found in areas with a history of industrial activity, improper waste management, or heavy usage of firefighting foam. It can contain dangerously high levels of PFAS.

2. Traditional Brick Making: The standard brick manufacturing process involves shaping the clay into bricks and then firing them in a kiln. This process includes steps like mixing the clay with other materials, molding it into brick shapes, and allowing these bricks to dry before firing.

3. Intense Heat Treatment: The crucial element of Bensdorp’s innovation is subjecting the contaminated clay soil to high temperatures in a kiln. Kilns typically reach temperatures between 900 and 1,200 degrees Celsius. These extreme temperatures play a vital role in breaking down PFAS chemicals.

4. Defluorination: The high kiln temperatures initiate a chemical reaction known as defluorination. This process effectively dismantles the long chains of fluorine atoms that make up PFAS. PFAS is known for its strong carbon-fluorine bond, which is notoriously difficult to break. However, the sustained high temperatures in the kiln facilitate the breakdown of this bond.

5. PFAS Elimination: As the clay soil is exposed to these elevated temperatures during the brick firing process, PFAS chemicals are completely eradicated. By the end of the process, there are no detectable traces of PFAS remaining in the final product – the bricks.

6. Safe and Clean End Product: The resulting bricks are entirely free from PFAS contaminants and can be used in construction and various other applications without posing any risk to the environment or human health. The removal of PFAS makes these bricks a safe and sustainable building material.

Environmental Impact and Sustainability:

One of the crucial aspects of this innovation is its environmental impact. PFAS pollution is a severe concern, especially in areas where industrial activity, improper waste disposal, or heavy use of firefighting foam have led to high levels of PFAS in the soil. Conventional solutions for dealing with contaminated soil have mainly involved storing it in depots, which doesn’t eliminate the problem. Emy Bensdorp’s approach offers a sustainable solution to address PFAS pollution at its source, ensuring that contaminated soil is genuinely cleaned.

Scalability and Practicality:

While it’s theoretically possible to use contaminated soil for making various ceramic products, bricks emerge as the most practical choice. The scalability of brick production, the familiarity of existing manufacturing processes, and the fact that no significant changes are needed in infrastructure make it a highly promising solution. Bensdorp’s approach capitalizes on the efficiency and convenience of existing brick production while addressing a significant environmental issue.

A Solution for the Future:

Bensdorp’s work is not just an academic exercise. She has successfully transformed heavily contaminated clay soils into clean bricks, with indicators marking the location of origin and the amount of PFAS removed. This practical application is a promising step toward solving the PFAS pollution problem.

Currently, contaminated soils are typically stored in depots and covered with sand. One such contaminated site is the land around Amsterdam’s Schiphol Airport, where a firefighting foam accident led to exceptionally high PFAS concentrations in the soil. Another affected location is in the city of Doetinchem in the province of Gelderland, where 1300 barrels of PFAS firefighting foam have leaked into the soil over many years. Bensdorp takes these clay soils and turns them into bricks with various colours, marking them to indicate their place of origin and the amount of PFAS removed.

The Next Step:

Looking ahead, Emy Bensdorp plans to demonstrate the scalability and practicality of her idea by producing 50,000 bricks from one site. This will be an important step in confirming that the process can work on an industrial scale and that it’s a viable solution for addressing PFAS contamination. The testing of emissions during this larger-scale production is also essential to ensure the entire process is environmentally friendly.


Emy Bensdorp’s innovation holds great promise in providing a sustainable and effective solution to a pressing environmental issue – PFAS pollution. By integrating her approach into the existing brick manufacturing process, she not only cleans contaminated soil but also contributes to the construction industry’s sustainability.



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