Refrigerants & environment
ChemSec: Single-Phase Liquid Cooling for Data Centers Already Works Without PFAS; Two-Phase Alternatives Still in Development
The ChemSec report, with technical support from Fraunhofer IZM (October 2026), systematizes PFAS-free alternatives for electronics cooling. Single-phase liquid systems — both immersion and direct-to-chip — already function without fluorinated heat-transfer fluids. Two-phase solutions, where the fluid evaporates during heat removal, remain in the pre-commercial stage; ChemSec questions the 13.5-year grace period proposed by the EU for restricting PFAS in two-phase immersion cooling.
PFAS-Free Alternatives for Data Center Cooling: What Is Ready and What Is Still in the Pipeline
The ChemSec report, "Seek and you shall find: Alternatives to PFAS in electronics," published in October 2026 with technical support from Fraunhofer IZM, examines eight application areas for PFAS in electronics — from printed circuit boards and cables to heat-transfer fluids. For cooling systems, the document distinguishes between technologies already operating without fluorinated heat-transfer fluids and those still in the pre-commercialization stage.
Single-Phase Liquid Cooling: No PFAS Required
According to the analysis, single-phase liquid cooling systems — both immersion-type and direct-to-chip liquid contact — are capable of functioning without PFAS-containing heat-transfer fluids. This is why the report's main focus shifts to two-phase systems, in which the fluid evaporates during the heat-removal process.
In two-phase applications, fluorinated liquids are used for two properties: electrical non-conductivity and the ability to formulate compositions for various boiling temperatures.
Two-Phase Alternatives: Development Status
ChemSec cites several examples of PFAS-free solutions for two-phase cooling:
- ZutaCore — in 2023, the company announced its intention to bring a two-phase, PFAS-free liquid for direct chip cooling to market in 2026. The report notes that no subsequent confirmation of the availability date has been found.
- Blue Wolf Fluids — offers fluids claimed to be PFAS-free for two-phase immersion cooling. The authors point to the limited information on their actual commercial deployment.
Microchannels in Silicon: TSMC and Microsoft
A separate section of the report is devoted to technologies in which the cooling fluid is delivered through microchannels etched directly into the silicon or integrated into the chip structure. Among the mentioned developments are projects by Microsoft and TSMC. For TSMC, the report states that prototypes are being tested with deionized water, with a target commercial deployment date of 2027. Questions of mass production and fluid purity to prevent corrosion remain unresolved.
Regulatory Aspect: A 13.5-Year Grace Period
Based on the identified alternatives, ChemSec questions the proposed 13.5-year grace period from the entry into force of the EU restriction on PFAS used as heat-transfer fluids in two-phase immersion cooling.
At the same time, the document emphasizes that the feasibility of replacement must be assessed on a case-by-case basis, especially when multiple extreme performance requirements are imposed simultaneously.
Methodology and Limitations
The review is based on scientific literature, manufacturer documentation, questionnaires, and interviews. The authors explicitly state that it is not an exhaustive list of applications or available alternatives.
Source: ZeroSottoZero
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