3M Fluorinert Electronic Liquids: FC-70 and FC-770

Published July 2026

Electronics generate heat, and at some point air stops being able to move enough of it. 3M Fluorinert Electronic Liquids are one of the standard answers to that problem. These are a family of fully fluorinated liquids used for direct-contact cooling where conductive coolants aren't an option. That problem is especially acute at DOE facilities running high-performance computing systems, where power density has outpaced what air cooling can handle.

Below is a rundown of what FC-70 and FC-770 are, where each is typically used, and how Government Scientific Source (GovSci) can help you source them through our federal contract vehicles.

What Fluorinert Is

Fluorinert is a family of fully fluorinated, chemically inert liquids developed by 3M for direct-contact cooling of electronic and electrical equipment. "Chemically inert" is not a marketing term here. It means the fluid won't react with metals, plastics, or the sensitive components it's submerged against. It's also non-conductive, non-flammable, and leaves no residue on evaporation, which is the entire point of the product category.

The underlying chemistry is perfluorocarbon-based, which is what gives the fluids their combination of thermal stability and chemical inertness. Because the fluorine-carbon bond is strong and the molecule has no reactive sites, Fluorinert doesn't degrade the way hydrocarbon-based coolants can under normal operating conditions.

That stability has limits, though. Fluorinert can decompose if it's heated well beyond its recommended operating range or exposed to electrical arcing, so staying within the manufacturer's temperature and use guidelines matters. It also doesn't leave conductive residue behind if it evaporates off a board, which matters for anything getting powered back on afterward.

Two grades cover most use cases:

Fluorinert FC-70: Higher boiling point (215°C), used where sustained high-temperature stability matters — high-temperature reflow and thermal shock testing.
Fluorinert FC-770: Lower boiling point (95°C), chosen primarily because that boiling point enables two-phase immersion cooling — not simply because it operates at a lower boiling point.

The boiling point difference is the main thing driving which grade gets used where. FC-70's higher boiling point makes it useful in processes that involve sustained exposure to elevated temperatures without the fluid itself changing phase.

FC-770's lower boiling point puts it in the right range to vaporize at the heat source and condense elsewhere in the system in a two-phase setup — a more active form of heat transfer than straight immersion, and the actual reason it gets selected for that role rather than simply being "the cooler option." Both are used across semiconductor testing, avionics, power electronics, and immersion cooling for high-density computing.

Electronic Liquid Cooling, Briefly

Air cooling has a ceiling. As power density in servers, RF equipment, and lab instrumentation climbs, air simply can't move enough heat fast enough. Liquid cooling —specifically dielectric liquid immersion — solves this by submerging components directly in a non-conductive fluid, eliminating the air gap and the fans that used to compensate for it.

Fluorinert is one of the few fluids suited to this because it's non-conductive. Water-based coolants require isolation from live electronics, which adds complexity and failure points; Fluorinert doesn't need that isolation.

There are two general approaches to immersion cooling, and the choice of fluid tends to follow the approach:

Single-phase immersion: Components sit fully submerged in liquid that stays in its liquid state throughout. Heat moves from the component into the fluid, and the fluid is circulated to a heat exchanger. This is the more common setup and tends to use higher-boiling-point fluids like FC-70.
Two-phase immersion: The fluid is chosen so that heat from the component causes localized boiling. The vapor rises, condenses against a cooler surface (often a coil at the top of the tank), and drips back down as liquid. This is more thermally efficient per unit of fluid but requires tighter control over the system, since the fluid's boiling point has to line up with the equipment's operating temperature. FC-770 gets selected for this role specifically because its boiling point falls in that usable range — not because it's simply the lower-temperature option.

Neither approach is inherently better. It depends on the heat load, the equipment's tolerance for direct fluid contact, and how much complexity the facility is willing to manage in exchange for cooling efficiency.

Relevance to DOE Facilities

DOE national labs operate some of the highest power-density computing environments in the country, including several of the world's fastest supercomputers. At that scale, the cooling infrastructure required to keep systems operating has become as much of an engineering problem as the computing itself. Air cooling isn't viable at that density, and even conventional liquid cooling (cold plates, rear-door heat exchangers) has limits.

Immersion cooling with dielectric fluids like Fluorinert is one of the approaches being evaluated and deployed to push past those limits, since it removes heat directly at the component level rather than relying on a secondary loop.

Fluorinert isn't the only fluid family in that conversation, though. 3M's own Novec line, Solvay's Galden perfluoropolyethers (PFPE), and various custom-blended dielectric fluids are also used as alternatives or replacements depending on the application and the environmental profile a facility is trying to manage.

Outside of HPC, Fluorinert also shows up in DOE-adjacent work involving radiation-detector cooling, particle physics test setups, and stockpile stewardship-related simulation hardware. Applications where equipment is sensitive to both heat and the introduction of conductive or reactive materials nearby.

In those contexts, it's typically chosen for its low surface tension and chemical inertness rather than any particular suitability for vacuum environments, properties that let it wet complex geometries evenly and avoid reacting with the materials it contacts.

Handling and Storage Notes

Fluorinert's chemical stability makes it low-maintenance relative to other lab fluids, but a few things are worth noting for anyone stocking it:

It should be stored in tightly sealed containers, since prolonged exposure to air and moisture can introduce contaminants that affect its dielectric properties.
Fluorinert is not classified as hazardous under most standard frameworks. However, it should still be handled with the same basic PPE expected for any lab fluid — gloves and eye protection, primarily to avoid contamination of the fluid itself rather than any inherent toxicity concern.
Cross-contamination between grades (FC-70 and FC-770, for instance) can shift the fluid's boiling point and degrade thermal performance in two-phase systems, so labs running multiple grades should keep them in clearly separated, dedicated containers.

PFAS Considerations

Fluorinert's chemical stability comes from the same fluorine-carbon bonds that place it within the broader PFAS (per- and polyfluoroalkyl substances) category—a group of chemicals receiving increased regulatory and environmental scrutiny.

While Fluorinert's regulatory status differs from the PFAS compounds most commonly associated with drinking water contamination, its use is still an important consideration for procurement, handling, and long-term planning.

A few practical implications:

Disposal isn't as simple as pouring it out. Used or contaminated Fluorinert should be managed through your facility's established hazardous or specialty waste procedures rather than general laboratory waste.
Regulatory treatment of PFAS continues to evolve at both the federal and state levels, so facilities using Fluorinert should periodically review updated guidance to ensure continued compliance.
Interest in alternative dielectric fluids has increased in recent years as organizations evaluate options with different environmental and regulatory profiles. At the same time, 3M completed its exit from PFAS manufacturing, making Fluorinert a legacy product line with more limited long-term availability. Existing systems continue to rely on Fluorinert, but many new projects are also evaluating alternatives such as Galden PFPE fluids, engineered hydrocarbon dielectric fluids, and other specialty coolants.

None of this makes Fluorinert unsuitable for federal laboratory applications. It remains a well-characterized and widely used dielectric fluid in existing installations. However, facilities planning new systems or long-term procurement strategies should consider both the evolving regulatory landscape and the availability of alternative cooling fluids when selecting a dielectric coolant.

Sourcing Fluorinert

GovSci distributes 3M Fluorinert Electronic Liquids, including FC-70 and FC-770, under GSA Schedule, ECAT, Intramalls, and ICPT contract vehicles. These paths for federal facilities can help avoid a sole-source justification for a specialty fluid.

Lead times and pricing on Fluorinert can vary depending on order volume and grade, since it's a specialty chemical rather than a stocked commodity item at most distributors. Working through an established distributor with existing contract vehicles in place typically shortens that process, since the compliance paperwork is already established.

For current pricing or availability on Fluorinert FC-770 or FC-70, contact GovSci. You can also register now to shop online.