Gravel2Gavel Construction & Real Estate Law blog — May 2, 2025
The historic or future use of these chemicals may create liabilities, obligations, or new costs for both existing and planned data centers. The use of these chemicals in the past or in the future may result in liabilities, obligations or new costs to existing or planned data centers.
PFAS in Data Centers
Perfluoroalkyl Substances (PFAS) have been widely used in a variety of products and industries for decades. The carbon-fluorine bonds are among the strongest in organic chemistry, and give PFAS their physical characteristics: fire, oil and grease resistance. These properties, such as chemical stability, resistance to degrading, and oil and moisture resistance, make PFAS useful, but also concerning from an environmental perspective. They tend to persist in the atmosphere and bioaccumulate within living organisms. PFAS are defined differently by different regulatory bodies. The most expansive definitions of PFAS are those adopted by certain states that classify as PFAS any chemical featuring a carbon atom that is saturated with fluorine.
PFAS that meet this definition serve several necessary functions with respect to data centers. Certain server components, cables, and switchgears are either coated or integrated with PFAS. Fluoropolymers are not only found in data center equipment. Fluoropolymers, because of their relative stability, are less bioaccumulative and toxic than long-chain alkyl-PFAS (i.e. straight-chain PFAS whose molecular backbones are at least seven-carbons long). PFAS are used in chillers and air conditioning units because of their low melting point and fire resistance. Overheating can cause a fire risk, which is exacerbated due to the concentration of electrical and combustible materials such as cabling and plastics. As such, data centers are equipped with fire suppression systems, which may contain PFAS.
PFAS in Fire Suppression Systems
Because data centers are packed with server racks, they require fire suppression systems that will not destroy the equipment. The best suited are dry pipe fire sprinkler systems and a clean agent fire suppression system.
Historically, dry pipe fire suppression systems have used Class B aqueous film-forming foams (AFFF) and automatic reactivation AFFF. These AFFF formulations can contain PFAS. The activation of fire suppressor systems may result in a sudden discharge of PFAS containing AFFF. Furthermore, the long-chain alkyl PFAS present in AFFF–perfluorooctanoic acid (PFOA) and perfluorooctane sulfonic acid (PFOS)–are dispersible in the environment and (a) subject to stringent de facto cleanup standards in the form of maximum contaminant levels of 4 parts per trillion (ppt) in groundwater, orders of magnitude lower than those for other industrial chemicals, and (b) formally designated as hazardous substances under the Comprehensive Environmental Response, Compensation, and Liability Act (CERCLA), meaning that sites contaminated with these chemicals are subject to strict, joint and several liability. Multidistrict litigation involving AFFF discharge to the environment has resulted in some of the largest PFAS-related settlements. To date, 15 States (AK, CA CO, CT, HI ME MD MN, NJ, NY RI VT WA) have banned firefighting foam containing PFAS. The market for synthetic fluorine free foams is growing. However, SFFFs do not have the same efficacy as AFFF technologies.
Clean fire suppression systems use gaseous agents to quickly extinguish fires, leaving no residue behind, which makes them ideal for protecting sensitive equipment and areas where water damage would be undesirable. The most commonly used clean agents like FK-5-1-12 (Novec 1230), HFC-227ea (FM-200), HFC-125, HFC-236fa, and 2-bromo-3,3,3-trifluoropropene are PFAS under various definitions, though they have different properties from PFOA and PFOS and are not subject to CERCLA regulation. Even so, data centers may be regarded as a target for litigation in areas where contamination with fluorinated organic compounds has been identified.
HFC-Refrigerants
- Hydrofluorocarbons (HFCs) are synthetic chemicals commonly used in commercial refrigeration and cooling systems. Data centers produce large amounts of heat and often need complex cooling systems to ensure their systems do not overheat.
Starting in the 1990s, HFCs came to replace traditional refrigerants, classified as ozone-depleting substances, in the aftermath of the 1987 Montreal Protocol. HFCs are greenhouse gases and therefore pose an environmental risk. Studies have shown that HFCs are more potent than carbon dioxide in terms of global warming. The data center industry has to deal with a regulatory framework that is increasingly focused on HFCs. Hydrofluoroolefins (HFOs), which are increasingly being seen as alternatives to HFCs, have a lower global warming potential but may carry their own risks such as flammability.
Congress passed the American Innovation and Manufacturing (“AIM”) Act of 2020, mandating an 85% phasedown of HFC production and consumption by 2036. Under the Biden administration, the U.S. Environmental Protection Agency (EPA) moved aggressively to implement the AIM Act through a suite of interconnected regulations:
A cap-and-trade system, which became effective on November 4, 2021, and which is intended to phase down over time the total volume of HFCs in the U.S. market.
The Technology Transition Rule, 88 Fed. Reg. 73098 (October 24, 2023), restricting the use of most HFC-based refrigerants in new equipment.
The Emissions Reduction and Reclamation (ER&R) Rule, 89 Fed. Reg. This regulatory approach could impact both existing and new data centers. Existing data centres that rely on the HFCs could be affected by the ER&R Rule, which imposes extensive compliance obligations and may be costly for such systems. Operators of existing systems could be required to install automatic equipment for leak detection, comply with detailed recordkeeping requirements and repair leaks as soon as they exceed certain thresholds. They may even be required retrofit or retire any systems that are not able to be repaired within a specified timeframe. The Technology Transitions rule will remove HFC-based cooling systems from the market, which may impact new data centers. For example, new data centers systems will be legally prohibited from using systems that rely on R-410a, a popular refrigerant in data center cooling systems.
- Despite the increasing availability of alternative refrigerants coming onto the market, it may be difficult to retrofit existing refrigeration systems to use these products. Additionally, the new refrigerants–including some that are HFOs and hydrochlorofluoroolefins–may present other risks not customarily associated with HFCs. For example, A2L refrigerants may raise new concerns due to their flammability, CO2-based systems may require higher energy consumption particular in warmer climates, and adiabatic cooling (heat reduction via pressure drop) may be water-intensive and therefore unsuitable for drier regions.
- RELATED ARTICLES
- PFAS in Fire Protection Products Continues to Generate Litigation, Liability
Fire-Resistant Turnout Gear Represents a New Frontier in PFAS Liability
