Uptime is essential in food manufacturing. Even short interruptions can disrupt entire processes, resulting in lost product and reduced profitability. According to an IDS-INDATA report from April 2025, equipment downtime can cost food manufacturing operations between $24,000 and $33,000 per hour. For facilities operating industrial fryers, a significant part of maintaining uptime is having effective fire suppression systems in place.
Traditionally, food manufacturers have leveraged carbon dioxide (CO2) gas as a fire suppressant for protecting industrial fryers. However, recent discoveries about water mist systems are unlocking new opportunities for industrial fryer protection (IFP) that can drive both safety and profitability.
Both CO2 and water mist fire suppression systems offer Factory Mutual (FM) Approved and EN14972 compliant solutions, but there are several important factors to consider when determining which system is right for your operation. Factors like overall fire suppression effectiveness, third-party testing, system footprint and environmental health & safety (EHS) risks can differ between the systems. This guide will compare the two solutions to help specifiers and facility teams make the most informed decision to protect their operation.
Comparing System Effectiveness
CO2 fire suppression systems work by releasing carbon dioxide gas to displace the oxygen surrounding the fire. Without oxygen, the fire is extinguished. However, the CO2 does not effectively lower the fryer oil temperature since it does not have strong cooling abilities. Even after initial flames are extinguished, oil temperatures within the fryer may still be at or above the auto-ignition point (between 644 and 833 degrees Fahrenheit or 340 and 445 degrees Celsius). When oxygen is eventually reintroduced into the environment, fire auto-reignition, also known as reflash, can occur.
In comparison, water mist fire suppression systems discharge a low-pressure water vapor/fog. These droplets are so small that they evaporate before coming into contact with the heated oil, which prevents micro explosions typically associated with the mixture of water and hot oil (no boiling delay). Ultra-fine water mist vapor droplets hover above the oil surface, where they evaporate, create steam, cool the area and push away oxygen to effectively suppress fire.
At the same time, larger mist droplets penetrate the flame and reach the surface of the oil. There, they absorb heat from the oil (cooling effect) and evaporate, producing large amounts of steam, which creates an inert gas/atmosphere in the area directly surrounding the flame. This rapidly extinguishes the flames and cools the oil below its auto ignition temperature to successfully prevent fire reflash.
EHS Factors
While CO2 can be an effective fire suppression agent, it presents potential health and safety risks for personnel in the direct vicinity of a discharged system. The National Fire Protection Association (NFPA) 12 guidelines require human evacuation 20 to 60 seconds before the CO2 agent can be released.[i] This delay is a necessary life safety precaution, though postponing suppression can increase the threat and damage of a fire event.
Because of this potential risk, food manufacturers using CO2 systems must adhere to additional EHS protocols, which require establishing and maintaining safe escape routes and training staff to support safety procedures.
Even after these processes are complete and a fire event is resolved, manufacturers often face additional downtime to ensure the environment is safe again for workers. Before personnel can reoccupy the area, the local fire brigade must first determine that CO2 has been sufficiently ventilated to safe levels.
Comparatively, water mist systems use potable or filtered water as a fire suppressant. Because only water is used, the system does not present a life safety risk for workers within its vicinity. This creates a significant advantage in maintaining a safe environment for the teams who work in these spaces and helps reduce downtime surrounding a fire event.
Following a system activation, a water mist system can be returned to service much faster than a CO2 system, helping to reduce operational downtime and minimize costs for the end user. That’s because with CO2 systems, empty (released) CO2 cylinders must be refilled and/or replaced after an activation, which drives the downtime of the fryer.
After a water mist activation, it is best practice for facility teams to first clean their fryer, then replace the nozzles protecting the fryer. Operators should also check the water supply and filters before taking the water mist system back to operation. These jobs can be done simultaneously with no notable downtime caused by the water mist system. By having a water mist system in place, teams can put their fryer back in operation immediately after its cleaning.
System Components
Fire suppression system components are important to consider when specifying industrial fryer protection because they can impact available floor space, storage, installation needs and potential integration with other building systems.
For example, due to their low water consumption, FM Approved water mist systems can use a facility’s existing fire sprinkler water supply and can connect directly to the tank. Since water mist systems only use this water supply, there’s no additional tank required for a separate fire suppression agent. Low-pressure water mist systems also have reduced pipe weights, lower required power supplies (mains connection), lower pump cost and less energy requirements compared to high-pressure water mist alternatives.
In comparison, CO2 systems require separate fire suppression medium cylinders which require additional floor space and could pose a challenge to smaller food manufacturing facilities.
Industry Testing
When selecting a fire suppression system, it is necessary to look for a solution that has undergone and received FM Approval specifically for the protection of industrial fryers. Both water mist and CO2 fire suppression systems undergo testing for global approvals like UL/ULC and FM. That testing data suggests that water mist should not only be considered but heavily favored as a fire suppression solution for industrial fryer protection.
This conclusion was reinforced during the FM 5560 Appendix J “Industrial Oil Cooker Test” of the Johnson Controls AquaMist ULF water mist fire suppression system, done in 2013. During that test, the water mist system was able to extinguish all open flames within one minute of discharge and eliminate the potential for auto-reignition in both hood-up and hood-down positions. Water mist effectively lowered the average oil temperature below 392 F (200 C) to prevent thermal damage and was able to discharge for twice the amount of time required to extinguish the worst-case fire scenario (minimum 10 minutes). During the discharge of the water mist system, there were no fire flare-ups, micro explosions of oil reacting with water or splashing of the burning oil. The testing resulted in the full approval of AquaMist as a complete water mist fire suppression system.
Selecting Water Mist Protection for your Industrial Fryer
Today’s advanced water mist fire suppression systems create a compelling alternative to CO2 suppression systems. When looking for effective and reliable industrial fryer protection, fried food producers need to consider fully-approved low-pressure water mist systems not only for safety but for business continuity. Water mist systems can reduce the severity of a fire event as well as reduce EHS and space needs compared to CO2 systems. By effectively suppressing fire and cooling the oil, water mist systems offer superior protection for industrial fryers backed by real industry testing.
Today, hundreds of industrial oil cookers have been protected by the rigorously tested and approved AquaMist ULF IFP low-pressure water mist system all over the globe.
Please visit https://tycoaquamist.com/industries/industrial-fryer-protection/ for more information.
About the Author
Dirk Laibach has over 30 years of varied global experience in the fire suppression and detection industry, including 23 years in Water Mist. He has held positions of increasing responsibility with Siemens, KIDDE , FOGTEC Fire Protection, Marioff and currently as Global Senior Product Manager for Water Mist at Johnson Controls.
Dirk Laibach, Global Senior Product Manager for Water Mist at Johnson ControlsJohnson Controls
Through his involvement and membership in a number of trade associations, codes and standards organizations (CEN) and approval authorities (like VdS, FM) in Europe and the USA. He also has extensive relationships within the industry and AHJ bodies. He is a board member of the International Watermist Association (IWMA).
Dirk holds a degree in electrical engineering (Dipl.-Ing.) from the University of Applied Sciences Düsseldorf, Germany, and is a VdS-certified engineer for Water Mist Fire Suppression Systems.