Per- and polyfluoroalkyl substances (PFAS), known as “forever chemicals,” pose a number of health risks to humans, with more suspected but not yet confirmed – and, as a result, PFAS are coming under increasing regulatory scrutiny. Last July, some members of the cooling industry warned that PFAS regulations in Europe could disrupt the semiconductor industry. Then, later in the year, the U.S. Environmental Protection Agency (EPA) moved to designate PFAS as hazardous substances – a change that introduces new regulatory requirements for companies that continue to use those substances – and announced plans for a number of measures to better alert civilians of PFAS-induced health risks.

Now, Buffalo-based cooling firm Motivair has published an article suggesting that the EPA’s moves against PFAS, along with a recent industry exit by 3M, may significantly impact the HPC industry’s deployment of two-phase immersion cooling and two-phase cold plate cooling solutions.

Motivair specifically focused its commentary on the two-phase solutions: single-phase immersion cooling, the firm explained, uses a non-conductive oil; single-phase cold plate cooling uses a water-based fluid. Motivair wrote that the two-phase variants of both – in which the cooling liquid is boiled, then condensed, rather than remaining in a liquid form – use substances like Novec, the 3M-manufactured PFAS that was at the center of the aforementioned warning to the semiconductor industry last summer.

Motivair identified three emergent factors for the HPC industry. The last-listed, but perhaps most relevant: in the wake of the Belgian plant shutdown and the EPA designation, 3M – which manufactures the bulk of PFAS – announced in December its intent to exit PFAS manufacturing by 2025, posing (in Motivair’s words) an “immediate risk of obsolescence” for those employing PFAS-reliant cooling technologies.

Second: manufacturers and major players tend to operate globally, which introduces the California effect, whereby more restrictive regulatory regimes (like the EU) might drive industry trends well outside their ostensible jurisdiction. In this way, the EPA designation might slow moves toward two-phase cooling in more permissive areas.

And, finally, Motivair noted that major players (Google, Meta, etc.) tend to have ESG goals that might make them shy away from PFAS even if its use were legally and logistically feasible. The company concludes that while two-phase cooling technologies “will find a home within the larger IT ecosystem,” the recent scrutiny on PFAS “will continue to present challenges to large-scale adoption moving forward.”

“Those technologies capable of meeting performance needs, ESG goals, and supply chain continuity will most likely command the most attention moving forward,” they write.

Outside of the cooling community, others were skeptical of the material difference the new regulations will make to the trajectory of high-performance computing.

“Dell Technologies has been evaluating two-phase cooling technologies for nearly a decade,” Tim Shedd, an engineering technologist for Dell, told HPCwire. “Our conclusions from this work are well-aligned with the rest of the HPC field: direct-to-chip liquid cooling using a water-based coolant is preferred. Water-based liquid cooling is safe and effective and can allow our customers to achieve dramatic gains in sustainability and energy efficiency while at the same time deploying orders-of-magnitude more powerful computing systems. We don’t anticipate the referenced restrictions to have a significant impact on the future of HPC.”

Dan Stanzione, director of the Texas Advanced Computing Center (TACC), shared a similar perspective. “We ought to be able to get above 1.5kW per socket with single-phase,” Stanzione told HPCwire, “so I don’t think there is anything short-term (~next five years) that we can’t do now, or where our plans would have to change.[.]”