The Environmental Protection Agency (EPA)’s designation of polyfluoroalkyl substances (PFAS) as “forever chemicals” is having a major impact on how data centers cool their AI and high-performance computing (HPC) implementations.
PFAS, which appear in cleaning agents, refrigerants, waterproof clothing, and non-stick materials, are also used in two-phase immersion cooling and two-phase direct-to-chip cooling. Under the Toxic Substances Control Act (TSCA), PFAS manufacturers, processors, and distributors were supposed to begin reporting their use of PFAS in 2024, but after three extensions by the EPA, the reporting deadline has been pushed back to January 31, 2027.
Data center operators are among the organizations that must report PFAS use once the requirements take effect. While TSCA doesn’t ban PFAS outright, the reporting requirements are intended to control their use and, eventually, phase them out.
States such as New Jersey, Maine, Massachusetts, Minnesota, and Washington already have – or are planning to – impose reporting requirements. “Forever chemicals” are nearly indestructible and have been linked to health problems in humans.
Research is under way to find natural fluorocarbon coolant alternatives. Progress has been slow but the pressure is on since 3M, the biggest producer of PFAS, has phased out production of chemicals such as Novec. The chemical had been used extensively in cooling systems, including two-phase immersion liquid cooling and two-phase cold plate cooling.
Some manufacturers, suppliers and data center operators are seeking exceptions in the use of PFAS because of the potential benefits. While these efforts are understandable, they are out of step with environmental, social, and governance (ESG) and sustainability strategies adopted by data center operators and other IT organizations. Once natural alternatives to PFAS become available, it’s likely that organizations will move quickly to adopt them to align with sustainability efforts.
There is no PFAS immersion cooling ban as of yet, but PFAS regulations and the discontinuation of Novec production have halted the growth of two-phase immersion cooling. The two-phase immersion method involves submerging servers and other hardware in dielectric fluids that absorb heat and undergo phase change into vapor. This vapor then recondenses into liquid after exchanging heat with coils at the top of the tank. The process is highly effective, but other liquid cooling topologies, especially single-phase direct-to-chip (DTC) cooling, are more popular.
As of 2026, single-phase DTC liquid cooling has become the dominant liquid cooling method, with a 55% market share. This PFAS-free liquid cooling method uses a solution of 75% water and 25% Glycol to remove heat from GPUs and high-density AI chips. The fluid is circulated in a closed-loop system called the TCS (technology cooling system) to a CDU to exchange heat to the FWS (facility water system). While chillers that sit outside the data center for heat rejection of the FWS may use some traditional refrigerants, certain climates may allow for the use of dry coolers or cooling towers.
From a sustainability perspective, single-phase DTC presents the most attractive option to data centers. Adding to the appeal are its ease of deployment and cost-effectiveness, compared to methods such as two-phase liquid cooling.
Ultimately, PFAS regulation is accelerating a broader shift in how data centers approach thermal management. What began as a compliance issue is quickly becoming a strategic decision that ties directly to sustainability goals and managing long-term operational risk.
As uncertainty around PFAS-based cooling persists, many operators are prioritizing proven, scalable alternatives that align with both performance and environmental expectations. Single-phase direct-to-chip cooling stands out not just for its efficiency and cost advantages, but for its ability to deliver high-density cooling without regulatory headwinds.
Schneider Electric, with Motivair, delivers a full suite of single-phase DTC solutions, including PFAS-free liquid cooling, for data center operators looking to cool AI and HPC deployments with minimal environmental impact. As the race to AI accelerates, data center operators need partners like Schneider Electric to support their growth while helping them align with evolving ESG standards.
