Industry Trends · 2026-10-30
PFAS Regulations Drive Immersion Cooling Fluid Trends
Explore the shift from fluorinated fluids to synthetic hydrocarbon coolants in AI data center immersion cooling under tightening global PFAS regulations.
Key takeaways
- Global regulatory phase-outs targeting PFAS 'forever chemicals' are accelerating the transition of AI data center single-phase immersion cooling toward fluorine-free synthetic hydrocarbons.
- Synthetic hydrocarbons offer favorable thermophysical properties: Eurotherm ICF-EV1 delivers a specific heat capacity of 2.0 J/g·K and thermal conductivity of 0.15 W/m·K, compared to roughly 1.22 kJ/kg·K for conventional fluorochemicals.
- Low-viscosity formulations lower pumping parasitics: Eurotherm ICF-EV4 exhibits a kinematic viscosity of 2.1 mm²/s at 40°C alongside a 45 kV breakdown voltage for reliable electrical insulation.
- High flash point grades enhance thermal safety margins: Eurotherm ICF-EV3 features an open cup flash point above 240°C, a boiling point exceeding 400°C, and operates across -20°C to 330°C in closed systems under nitrogen or cold-oil seals.
How Are Global PFAS Bans Restructuring Data Center Coolants?
As the European Chemicals Agency (ECHA) advances restriction proposals on per- and polyfluoroalkyl substances (PFAS) and major chemical producers schedule phase-outs of fluorochemical manufacturing, high-density AI computing facilities face compliance scrutiny and supply chain challenges. Environmental analyses show that conventional electronic fluorinated liquids, characterized by severe persistence and bioaccumulation in natural environments, are under mounting regulatory restriction globally.
To achieve power usage effectiveness (PUE) targets and support rack densities surpassing 100 kW, single-phase immersion liquid cooling architectures historically utilized perfluoropolyethers (PFPE) and hydrofluoroethers (HFE). Today, data center operators and thermal engineers are turning toward synthetic hydrocarbon fluids to avoid regulatory disruption, control total lifecycle fluid procurement expenses, and lower environmental liabilities.
Synthetic Hydrocarbons vs. Fluorinated Fluids: Thermophysical Profile
From a heat transfer standpoint, synthetic single-phase immersion coolants demonstrate distinct specific heat capacity advantages. Eurotherm ICF-EV1 provides a specific heat capacity of 2.0 J/g·K, whereas traditional fluorinated fluids such as Eurotherm HFP-04 measure approximately 1.22 kJ/kg·K. Higher specific heat allows the cooling loop to transport equivalent thermal loads at reduced volumetric flow rates, which decreases circulation pump power demand and lowers overall facility energy consumption.
Regarding dielectric integrity, low-conductivity synthetic hydrocarbons fully satisfy the insulation demands of sensitive computing hardware. Eurotherm ICF-EV1 and ICF-EV2 maintain electrical conductivities below 0.1 ps/m, while Eurotherm ICF-EV4 delivers a breakdown voltage of 45 kV and Eurotherm ICF-EV3 exhibits a dielectric strength of 39.4 kV. Unlike fluorinated fluids that operate in semi-open or evaporative baths, hydrocarbon coolants require closed systems with nitrogen blankets or cold-oil seals to prevent atmospheric oxygen ingress and avoid fluid oxidation.
| Product Model | Chemical Class | Operating Range | Kinematic Viscosity | Flash Point (Open Cup) | Dielectric Properties | System Requirement |
|---|---|---|---|---|---|---|
| Eurotherm ICF-EV4 | Synthetic Single-Phase (Low Viscosity) | -50 to 250°C | 2.1 mm²/s (40°C) | 108°C | Breakdown voltage: 45 kV | Closed systems only (nitrogen/cold-oil seal required) |
| Eurotherm ICF-EV1 | Synthetic Single-Phase (Hydrocarbon Base) | -50 to 150°C | 5–7 mm²/s (40°C) | >150°C | Conductivity <0.1 ps/m | Closed systems only (nitrogen/cold-oil seal required) |
| Eurotherm ICF-EV2 | Synthetic Single-Phase (Hydrocarbon Base) | -50 to 150°C | 10–15 mm²/s (40°C) | >190°C | Conductivity <0.1 ps/m | Closed systems only (nitrogen/cold-oil seal required) |
| Eurotherm ICF-EV3 | Synthetic Single-Phase (Broad Range) | -20 to 330°C | 31 mm²/s (40°C) | >240°C | Dielectric strength: 39.4 kV | Closed systems only (nitrogen/cold-oil seal required) |
| Eurotherm HFP-04 | Perfluorinated / Fluorinated Fluid | -85 to 70°C | 0.6 mm²/s (25°C) | No flash point (non-flammable) | High dielectric insulation | Open systems permissible (suggested ≤70°C) |
Engineering Selection Priorities for High-Density AI Racks
In single-phase immersion tank designs, kinematic viscosity and flash point remain key engineering selection criteria. In high-density server configurations featuring tight heatsink fin spacing, high fluid viscosity can restrict natural convection and induce excessive pressure drop. Eurotherm ICF-EV4 features a kinematic viscosity of 2.1 mm²/s at 40°C (27 mm²/s at -40°C) alongside a pour point below -60°C, providing low flow resistance and reliable cold-start fluidity.
For deployments requiring high thermal safety margins or wider operational temperature envelopes, high flash point synthetic coolants provide thermal stability. Eurotherm ICF-EV2 offers an open cup flash point above 190°C, while Eurotherm ICF-EV3 exceeds a 240°C flash point and a 400°C boiling point. Engineers can utilize the Suzhou Chemie online selector (https://calculator.szchemie.com.cn/select) to input operating temperatures, flow requirements, and allowable pressure drops to generate matched property curves.
Suzhou Chemie Immersion Fluid Portfolio and Migration Support
Covering operating temperatures from -115°C to 400°C, Suzhou Chemie manufactures synthetic dielectric cooling fluids across the Eurotherm ICF-EV1, ICF-EV2, ICF-EV3, and ICF-EV4 product families. In chemistry and thermal range, these formulations correspond to international benchmarks such as Shell Immersion Cooling Fluid S3 and S5. For specific semiconductor test benches or laboratory baths requiring open-bath handling during interim phase-out periods, Eurotherm HFP-03 and HFP-04 fluorinated fluids remain available.
Transitioning from fluorinated fluids to synthetic hydrocarbons requires careful material compatibility verification and cleaning protocols. Suzhou Chemie application engineers provide guidance on system retrofitting, fluid changeover, and seal evaluation—especially regarding EPDM, fluoroelastomers, and structural plastics. To consult on retrofitting pathways or request testing samples, technical teams may submit inquiries via the Suzhou Chemie contact portal (https://www.szchemie.com.cn/contact-us).
FAQ
Can existing fluorinated immersion cooling tanks be refilled directly with synthetic hydrocarbons?
No, direct mixing is not viable. Before transitioning from fluorinated fluids to synthetic hydrocarbons, system components including elastomeric seals, hoses, and venting structures must be verified. Synthetic hydrocarbons like the Eurotherm ICF series require closed-loop configurations with nitrogen or cold-oil sealing to isolate atmospheric oxygen, and any residual fluorochemicals must be thoroughly purged.
Will synthetic hydrocarbon immersion fluids damage server motherboards or cabling?
Eurotherm ICF series synthetic fluids provide high electrical insulation, with conductivities below 0.1 ps/m and breakdown voltages up to 45 kV for ICF-EV4. However, pre-deployment compatibility testing is necessary for structural thermoplastics, optical connectors, labeling adhesives, and PVC or PU cable jacketing to prevent softening or extraction.
How do engineers choose between Eurotherm ICF-EV4 and Eurotherm ICF-EV1?
Eurotherm ICF-EV4 features very low viscosity (2.1 mm²/s at 40°C), making it suitable for ultra-dense compute nodes with tight fin gaps that require minimal pumping resistance. Eurotherm ICF-EV1 has a viscosity of 5–7 mm²/s at 40°C, a flash point above 150°C, thermal conductivity of 0.15 W/m·K, and specific heat of 2.0 J/g·K, serving as a biodegradable option for general computing infrastructure.
Why do synthetic single-phase coolants require closed systems with nitrogen blanketing?
Synthetic hydrocarbons can experience gradual thermal oxidation when exposed to atmospheric air at elevated temperatures, leading to acid formation and viscosity drift. The Eurotherm ICF series is designated for closed systems; positive-pressure nitrogen or cold-oil seals eliminate oxygen and moisture ingress, preserving long-term dielectric strength and thermal stability.
Where can thermal designers find cross-reference data against international immersion fluids?
Engineers can consult the Suzhou Chemie cross-reference tool (https://calculator.szchemie.com.cn/compare) or the AI selection assistant (https://calculator.szchemie.com.cn/ai) to match existing commercial grades (such as Shell S3/S5 or 3M fluids) with technical parameters, or contact our engineering team via +86-512-66560280.
Sources
Product data are typical laboratory values for reference only; please confirm with a Chemie engineer.