The rapid expansion of AI data centers has already triggered fierce debates over their massive electricity consumption and water demands. Now, a quieter but potentially significant environmental issue is emerging: the growing use of PFAS, or 'forever chemicals,' in these facilities.
Data centers typically employ PFAS in two key ways: in their cooling systems and in the manufacturing of semiconductors. Industry advocates argue that PFAS-based cooling can dramatically cut water usage, addressing one of the biggest complaints about data center build-outs. But environmental scientists and activists warn that increasing reliance on these persistent compounds could worsen a global pollution crisis.
PFAS are a class of thousands of synthetic chemicals known for their strong carbon-fluorine bonds, which make them exceptionally resistant to degradation. They have been detected in water, soil, and human blood across the globe, and exposure to certain variants has been linked to cancers, fertility problems, liver and kidney damage, and immune dysfunction.
In data centers, PFAS are often used in closed-loop liquid cooling systems, where the chemicals circulate to absorb heat from servers. Kyle Doudrick, an environmental engineering professor at the University of Notre Dame, told The Hill that while these systems are designed to be sealed, 'no closed system is perfect,' and leaks are likely over time. 'Nothing is 100 percent sealed,' he added.
The American Chemistry Council, a trade group for chemical manufacturers, acknowledged that some data centers are exploring liquid cooling technologies that use PFAS. The group said these systems 'can help improve cooling efficiency and, in some cases, significantly reduce water use associated with traditional cooling approaches.'
Several major tech companies, including Amazon, Apple, and Google, told The Hill they do not currently use PFAS in their data center cooling processes. Amazon noted it has not adopted liquid immersion cooling, the technology most associated with PFAS concerns. However, the company did not respond to follow-up questions about other cooling methods. Oracle, Meta, and Microsoft did not respond to inquiries.
The Data Center Coalition, another industry lobby, acknowledged that 'virtually every industry contends with PFAS in its supply chain.' Vice President Michele Nellenbach said the industry 'takes compliance and accountability seriously' and works with regulators at all levels.
Critics remain unconvinced. Lenny Siegel, executive director of the Center for Public Environmental Oversight, warned that even closed-loop systems eventually leak, and the long-term disposal of PFAS remains unresolved. 'Closed loop is a great concept, but it doesn't deal with leaks or long-term disposal,' he said. Kate Manz, an assistant professor at the University of Michigan, said she would be concerned if she lived near a data center, noting that PFAS can degrade into trifluoroacetic acid, a chemical linked to thyroid issues.
The Trump administration has been eager to accelerate data center construction, including fast-tracking EPA approval of certain chemicals. The EPA says fast-tracking merely speeds up the start of reviews, not the risk assessment itself, and that fewer than ten chemicals have been expedited so far, including one PFAS. The agency is also considering several more PFAS compounds that could be used in data centers or semiconductors.
As the debate over data center impacts intensifies, the intersection of AI infrastructure and environmental health is becoming a flashpoint. For a deeper look at how communities are grappling with data center development, see this analysis. Meanwhile, state officials are also stepping in, as Texas moves to penalize data centers that evade water reporting. The political stakes are rising, with some lawmakers even urging impeachment to curb executive overreach on issues like this.
