First FM Approved water mist system for Hazard Category 2 and 3 occupancies, including data centers

In June 2025, FM Approvals certified the first-ever water mist system for the protection of non-storage occupancies for hazard category 2 (HC-2) and hazard category 3 (HC-3). The system, VID FIREKILL’s Low Pressure Water Mist System, has been tested and certified to the requirements of FM Approvals Examination Standard 5560 for Water Mist Systems.

Alex Palle, CEO of VID FIREKILL, explains “our mission is to protect property and business continuity with environmentally responsible fire protection solutions. FM Approvals plays a key role in that mission, challenging us to meet the highest performance standards in the World.” Palle adds, “We are proud each time we achieve a new certification with FM Approvals because it reflects the quality of our technology and sends a clear message to the market – FM Approved means trusted, tested, and ready to perform.” Additional information from VID FIREKILL’s perspective can be found on vidfirekill.dk.

With an FM Approved water mist solution for these higher hazard categories, for the first time it will make it possible to use an FM Approved system to fully protect all areas of most buildings whose maximum hazard is category 2 or 3. While there are longstanding FM Approved water mist applications for various equipment and hazards, the only general occupancy application for all of these was hazard category 1 (HC-1) – until VID FIREKILL’s Low Pressure Water Mist System became the first FM Approved solution for HC-2 and HC-3. Prior to this
FM Approval, it was only possible to use an FM Approved water mist protection system to protect light hazard occupancies included in HC-1. Complete definitions and details for hazard categories 1-3 can be found in FM Data Sheet 3-26 (Fire Protection for Non-Storage Occupancies).

HC-2 occupancies are predominately defined as areas with moderate continuous combustible loading with combustibles in processes or operations of moderate hazard due to limited quantities of plastics or ignitable liquids. Examples include manufacturing (machine shops, woodworking, electronics assembly, etc.) as well as retail, theaters, and food production.

HC-3 occupancies represent a higher fire risk compared to HC-2 and are predominately defined as areas with generally continuous higher combustible loading with limited quantities of ignitable liquids and heavier amounts of plastics. Higher ceiling heights and other factors that could increase fire spread often factor into an occupancy’s classification as HC-3. Water-based fire protection of HC-3 occupancies generally require more discharge than
HC-2 occupancies.

Some common facility types that are defined as HC-2 and HC-3 include data centers, industrial facilities, plastics manufacturing, vehicle manufacturing, and assembly plants. As an alternative to traditional fire sprinkler protection in these hazardous spaces, VID FIREKILL’s FM Approved water mist system has been tested and certified to the requirements of FM 5560. This certification confirms that VID FIREKILL can adequately protect these occupancies while utilizing approximately 50% of the water needed as compared to traditional sprinklers.

Data center fires can be catastrophic in many ways, and recovery after a fire can be very costly and time-consuming. A data center houses IT equipment used to collect, process, and store data for digital activities. Thousands of servers and cables are stored inside these facilities and due to the massive power density in the electrical equipment in server rooms, there is a great risk of equipment overheating and catching fire. Data centers need fast-acting fire suppression to protect equipment and safeguard business continuity. The VID FIREKILL Low Pressure Water Mist System provides effective and reliable fire protection for data centers and data processing equipment. Traditionally, data centers did not contain lithium-ion battery back-up units (BBUs). This changed in recent years, and they are now more common than ever. The presence of this new hazard has contributed to the evolution of data center protection requirements.

One of the primary motivators of VID FIREKILL obtaining FM Approval is to offer a tested and certified solution that can protect data center server halls that contain distributed lithium-ion BBUs. It is crucial to protect data centers from fire with minimal water due to the sensitive and expensive equipment housed inside. Water mist systems can effectively extinguish fires while keeping servers and other equipment intact and functional, which minimizes data loss and operational downtime.

According to Miguel Martinez, CCO of VID FIREKILL, “obtaining FM Approval for our water mist solutions marks a major technical and strategic milestone. From an R&D perspective, working with FM Approvals has pushed us to meet the most rigorous performance standards in the industry – validating years of innovation, testing, and engineering excellence."

Àlex Palau, CTO of VID FIREKILL, adds, “going through the certification process with FM Approvals pushes us to refine our systems and take performance even further. We also value the technical dialogue with FM Approvals. Their knowledge, experience, and openness help us make each product iteration better than the last.”

While FM Approvals has been evaluating traditional loss prevention products since 1886, we increasingly test and certify the performance of cutting-edge property loss prevention solutions – like those needed to adequately protect data centers. As industries, asset owners, and our customers innovate and evolve, we do the same by offering certification programs for their emerging areas of focus. Access the Approval Guide to review real-time information for all FM Approved products.

Protect your facilities with FM Approved loss prevention products. With 60,000+ FM Approved products, our globally recognized certification process is backed by technical integrity and confirms product performance under real-life conditions. If you manufacture loss prevention products or are in search of a solution to protect your facility from evolving risks, please reach out to us at [email protected] to learn more.