Castrol ON PG25 cooling fluids win NVIDIA data centre validation
Castrol has confirmed that its Castrol ON PG25 and PG25T direct-to-chip cooling fluids have been validated against NVIDIA's requirements for AI factory and data centre infrastructure. The milestone, announced on 18 August 2026, gives data centre operators, equipment manufacturers and cooling-system integrators additional assurance when specifying fluids for high-density AI workloads.
The validation covered a range of technical criteria: corrosion resistance, thermal stability, dilution-water quality, propylene glycol base-fluid purity, and material compatibility with the metals, plastics and seals that come into contact with the circulating fluid inside a closed-loop cooling circuit. NVIDIA's review also assessed Castrol's business practices and global supply-chain resilience, reflecting the growing emphasis buyers place on long-term vendor reliability rather than product performance alone.
The technology
Direct-to-chip liquid cooling routes fluid through cold plates mounted directly on processors, including CPUs and GPUs, to extract heat at the source rather than relying on ambient airflow. As rack power densities climb well above the thresholds that conventional air cooling can manage economically, this approach has moved from niche to mainstream in AI-optimised facilities.
The PG25 formulation operates as a closed-loop system with no atmospheric exposure, which the company says reduces evaporative water loss and improves water usage effectiveness (WUE). The PG25T variant uses an inhibited additive technology (IAT) package rather than the organic acid technology (OAT) used in the base PG25, offering operators a choice depending on system metallurgy and maintenance intervals.
Peter Huang, Global President of Thermal Management and Data Centres at Castrol, said: "The inclusion of Castrol ON PG25 and PG25T within NVIDIA-Validated AI Factory Infrastructure gives customers added confidence in both the fluids' performance and Castrol's ability to provide consistent global support across markets."
Market context
The liquid cooling sector is expanding rapidly as AI infrastructure providers move away from air-cooled architectures. Major coolant suppliers, specialist cold-plate manufacturers and hyperscaler infrastructure teams are all investing in validated fluid ecosystems, partly because a compatibility failure in a sealed loop can cause corrosive damage that is expensive and time-consuming to remediate. Vendor validation programmes from chip companies such as NVIDIA serve as de facto qualification gates, and appearing on such a list carries meaningful commercial weight in procurement conversations.
Castrol enters this market as part of the bp group, giving it manufacturing scale and a global distribution network that smaller specialist fluid vendors find difficult to match. Its competitors include established industrial chemistry firms and a growing number of startups targeting the data centre thermal management niche specifically.
From a regulatory standpoint, water usage is increasingly subject to local restrictions and sustainability reporting requirements. Closed-loop systems that reduce WUE are relevant to operators seeking to comply with emerging EU sustainability disclosure rules and local water-use permits in drought-affected regions. Castrol has not published specific WUE benchmark figures, so independent verification of those efficiency claims remains outstanding.
Castrol ON fluids are currently marketed across the US, Europe, the Middle East, China, Australia and South-East Asia. The company did not disclose any specific customer deployments or contract volumes alongside the validation announcement.