Data centers are swapping water for forever chemicals to keep AI cool

A new report from chemical watchdog ChemSec found that most of the world’s biggest PFAS producers are expanding their capacity thanks to AI infrastructure. PFAS, also known as “forever chemicals,” are being used to handle the enormous amounts of heat generated from data center equipment. The report found that major chemical producers—including Japanese conglomerate Daikin, French materials manufacturing company Arkema and American chemical company Chemours—are increasing PFAS production thanks to growing demand from semiconductor and data center industries. This stems from three main demand sources: data center cooling, semiconductor manufacturing and lithium-ion battery materials.

It seems to be a catch-22 from a noted criticism of data centers: water usage. Newer cooling systems in these facilities are using fluorinated chemicals that include PFAS instead of water. The world’s biggest makers of “forever chemicals” pulled in roughly $4 billion in profit in 2022, against an estimated $17.5 trillion a year in societal costs—healthcare, cleanup, contaminated water—according to an earlier 2023 analysis by ChemSec.

Thanks to the AI boom spurring data center development, the need to mitigate the effects of heat stemming from equipment may also drive up that demand for PFAS. This, while data center development continues growing: a 2026 study from the commercial real estate trade association BOMA found data center facilities accounted for nearly 46% of private construction last year, compared to less than 5% a decade ago. The actual dollar value of data construction spending exploded as well: from $1.8 billion in 2014 to $41.1 billion last year, per Statista.

The materials needed in the AI race

“Forever chemicals” are highly resistant to heat. That makes the chemical-bonded substances particularly useful in many common consumer products such as food packaging, stain-resistant sprays and firefighting foam. Due to the strong chemical bond of PFAS, it doesn’t degrade easily—making it dangerous for both humans and nature when exposed. That makeup also makes PFAS desirable in semiconductor manufacturing, industrial equipment and cooling systems, but that durability is also what makes their environmental, and health, footprint hard to cover.

In fact, that chemical durability is showing up in our lives. Data from the National Health and Nutrition Examination Survey found PFAS in the blood of 97% of Americans.

According to the ChemSec report, Chemours produces or uses more PFAS substances than any other on ChemSec’s list, per ChemSec’s SIN Producers database. The study also found the company is developing products intended for data center cooling as it expands its production of PFAS refrigerants. ChemSec estimates between half and two-thirds of Chemours’ $5.8 billion revenue comes from PFAS production. Daikin also plans to triple its PFAS capacity in response to semiconductor demand, according to the report, just as Arkema begins expanding production in North America and in Asia.

Data center cooling has already become a battleground. In July, 17 environmental organizations submitted a letter to the EPA to reject Chemours’ application to fast-track a new PFAS chemical—Opteon 2P50—for use in data center cooling. The groups argued that Chemours had underestimated the compound’s potential health and climate risks, and that the available toxicological evidence was insufficient.

“A hyperscale data center can contain hundreds of tanks, totaling tens of thousands of liters of dielectric fluid,” the letter read. “If even a small fraction of the Opteon 2P50 used in a large data center leaks, it would result in a significant release of PFAS gases. And when cooling tanks need to be replaced, large amounts of Opteon 2P50 will be disposed or released, increasing the risk to the public and the environment.”

Chemours has denied these concerns according to a report from The Guardian. The company said the system operates as a “closed loop” and the amount of gas escaping during operation is low. The chemical corporation has also continued moving forward in its data center cooling process, launching new refrigerants in August.

“AI is reshaping the demands placed on cooling infrastructure, and customers need solutions that can keep pace without compromising efficiency, reliability, or long-term regulatory readiness,” Joseph Martinko, President of Thermal & Specialized Solutions at Chemours, said in a press release. “Chemours is expanding the choices available to chiller OEMs and operators as they build and maintain the critical systems powering data centers, commercial buildings, and other mission critical environments, while further strengthening our position in attractive, high-growth cooling applications.”

Chemours did not immediately respond to a request for comment from Fortune.

French citizens have also filed a lawsuit against Arkema and Daikin on PFAS pollution allegations in January as well, citing concerns of “chemical valley.” The lawsuit included 192 citizens and four environmental organizations.

Arkema stated it “will defend itself before the court against the allegations contained in the summons,” and has separately pushed back on related contamination claims. Daikin said it has “accelerated its investments” since 2022 to better control its PFAS emissions.