When it comes to fire, commercial kitchens operate in a very high-risk environment. According to the most recent data from the National Fire Protection Association (NFPA), fire in eating and drinking establishments resulted in 110 civilian injuries and $165 million in direct property damage. Many of the affected businesses never recovered and had to close their doors for good.
Equipped with any number and combination of ranges, broilers, fryers and ovens operating at very high temperatures in close contact with fats, cooking oils, and other combustibles, commercial kitchens provide an ideal environment for fire. Not surprisingly, cooking equipment was responsible for more than 60 percent of the fires studied by the NFPA, underscoring the importance of following all fire extinguishing equipment requirements for the hoods, ducts, and cooking appliances used in commercial kitchens.
The NFPA 96 Standard for Ventilation Control and Fire Protection of Commercial Cooking Operations provides the requirements to help minimize fire risk and keep your employees and customers safe if a fire breaks out. The standards cover both automatic fire-extinguishing systems that provide primary protection as well as the portable fire extinguishers that provide secondary backup protection. This post will discuss the NFPA 96 requirements for portable fire extinguishers and wet chemical restaurant fire suppression systems. Wet chemical systems are the most common type of automatic fire suppression system used in commercial kitchens today and are recognized by the fire protection industry as the most effective fire suppression system for commercial kitchens available.
Class “K” Portable Fire Extinguishers are Required
One of the more recent changes in the NFPA 96 standard is the requirement for placards to be placed above all class “K” fire extinguishers stating that the automatic fire extinguishing system for the cooking appliance is to be activated prior to using the portable fire extinguisher. This change was made because today’s commercial kitchens use high-efficiency cooking appliances capable of extremely high energy input/output rates and vegetable oils that can ignite at high temperatures. When these oils ignite, they are already so hot that a portable extinguisher may not be effective.
Remember too, that even small fires can spread quickly. Activating the kitchen’s pre-engineered fire suppression system before reaching for the fire extinguisher is a better option for extinguishing the fire because it will eliminate the heat source by shutting off the electric or gas flowing into the appliance and quickly cover the hot cooking oil with the fire suppression agent.
Wet chemical fire suppression systems are extremely reliable. Given this, you might ask why you even need portable fire extinguishers. The answer is simple – any system can fail, and it’s possible for equipment that has been moved or grease spills that occur to spread a fire to an unprotected area. This is why the requirement for portable fire extinguishers in commercial kitchens remains in both the NFPA 96 and the NFPA 10 Standard for Portable Fire Extinguishers.
In order to handle the special cooking appliance fire hazards found in commercial kitchens today, you must use class “K” rated fire extinguishers. This is due to the large amounts of cooking oils and fats found in commercial kitchens. While these are technically flammable liquids, Class “B” extinguishers are not suitable to address the special kinds of hazards found in commercial kitchens. Class “K” fire extinguishers use chemical agents that react (saponify) with hot oils or grease to turn it into a non-flammable soap-like substance.
The code does not prescribe the size of the class “K” extinguisher to be used. A good rule of thumb is, the greater the hazard, the larger extinguisher you will need to handle it. However, it is always best to consult the Authorities Having Jurisdiction (AJH) prior to selecting new fire extinguishers for your kitchen to ensure you are in compliance with local codes.
Wet Chemical Fire Suppression Systems in Commercial Kitchens
The NFPA 96 requires automated fire suppression equipment for all grease removal devices, hood exhaust plenums, and exhaust duct systems in a commercial kitchen, as well as any cooking equipment that produces grease-laden vapors.
UL 300 Kitchen Fire Suppression systems are wet chemical fire suppression systems used to protect hoods, ducts, and cooking appliances from fire hazards. They are often referred to as “pre-engineered” systems, which means that they come from the manufacturer with specific specifications that are unique to that system. As such, their installation, repair and maintenance requires a properly trained and qualified technician that has been certified by the system’s manufacturer.
Wet chemical fire suppression systems work by releasing chemical agents that react with oil to create a thick foam that covers the entire cooking surface, smothering the burning oil until the appliance cools below the oil’s flash point. The effectiveness of these systems is not limited to fires that involve oil. The type of chemicals they use are very effective on all types of fires in a commercial kitchen.
The NFPA 96 requires that wet chemical pre-engineered fire suppression systems meet the requirements of ANSI/UL 300 or other equivalent standards that include fire test methods and requirements to protect the various types of cooking appliances and tests to evaluate the ability of pre-engineered equipment to protect plenums and ducts.
Not all grease removal devices, hood exhaust plenums, exhaust ducts, and cooking appliances are addressed in ANSI/UL 300 or other equivalent test standards. If your kitchen uses equipment that isn’t, you must make sure that any non-listed automatic fire suppression system installed is appropriate for the grease removal devices, hoods, ducts and cooking appliances you’re using based on the system manufacturer’s recommendations. The system must also meet all applicable NFPA standard(s), all local building and fire codes, and must be approved by the authority having jurisdiction. If you’re not sure if your system is UL-Listed, you can search the UL website using the manufacturer’s name and model number.
Installation and Operational Requirements
Wet chemical fire suppression systems use a suppression tank, which holds the chemical, and fixed piping with nozzles to discharge the chemical agent in the ductwork, plenum space, and cooking surfaces. It is critical that your system be designed for your unique kitchen and installed by contractors who have been certified by the system’s manufacturer. In some jurisdictions, the design may need to be submitted for approval by the AJH prior to installation. When the work is complete, the installer must provide certification to the AJH that the system was installed in accordance with the manufacturer’s recommendations and all relevant codes.
There are several operational requirements that must be considered during the design and installation. For example, when two or more hazards could be simultaneously involved in a fire based on their proximity, they are considered a single hazard area, and all fire suppression systems for each hazard must be set up to automatically operate simultaneously if any one of them is activated.
Generally, hoods installed end to end, back to back, or both, or those sharing a common ductwork with one or more grease-producing appliances located under any of them, are considered a single hazard area. In these cases, your fire suppression systems for each hood must be set to operate all at once if any one of them is activated to minimize the potential for fire to spread from one hood to another. The only exception to this is where the hoods do not share a common exhaust, are separated by a wall, or have some other means to ensure that grease-laden vapors from one hood cannot exhaust to another.
If properly installed, your wet chemical fire suppression system will provide the means for manual activation and will automatically shut off all sources of fuel and electrical power to the equipment protected by that system, including any gas appliance whether protected or not. Your means of manual activation can be mechanical or rely on electric power but must:
- Be readily accessible in the event of a fire and located in a path of egress
- Clearly identify the hazard protected
- Not require more than 40 pounds of force or have a pull movement greater than 14 inches (if using a cable pull device)
- Have a source of standby power (if using an electrical device)
In addition, you must have at least one manual actuation device between 10-20 feet from the protected appliances within the path of egress, and all manual activation devices must be separate from your system’s automatic means of activation so that failure of one will not prevent the function of the other.
The fact that the automatic fire suppression systems required in commercial kitchens include a manual component, underscores the need for training. It is critically important that your employees understand all the fire hazards that might be present in your kitchen. NFPA 96 requires all employees be provided training on the proper use of portable fire extinguishers and how to manually activate your fire suppression system in the event of a fire.
Generally, wet chemical fire suppression systems also must include a supervisory alarm with a reserve power supply to notify you if there’s a problem with the system. In addition, for establishments in which the kitchen is exposed to the dining area, the fire suppression system must also be connected to the fire alarm signaling system to alert your customers in the event of a fire.
Things to Know if You Modify Your Kitchen Set-up
Wet Chemical pre-engineered suppression systems are not portable systems and must be installed in accordance with their manufacturer’s instructions and the NFPA 17A NFPA 17A: Standard for Wet Chemical Extinguishing Systems.
If you move, reposition, or replace any of the cooking equipment in your kitchen, you must ensure that the fire suppression system for the appliance still meets ANSI/UL requirements, both in terms of how it is installed relative to the appliance and that it is appropriate for the appliance.
In addition, if you make modifications to existing hood systems in your kitchen, you must ensure that any abandoned pipe or conduit from the previous installation is removed from within the hood, plenum, and exhaust duct and any resulting holes or other penetrations be sealed.
Any changes to your grease removal devices, hood exhaust plenums, exhaust ducts, and cooking appliances will trigger the requirement to have your wet chemical fire suppression systems re-evaluated by a qualified technician to ensure it still complies with NFPA 96 and 17A requirements.
Remember, what may seem like a minor modification could change the hazard, potentially rendering your system ineffective. For example, manufacturers of the nozzles used in wet chemical fire suppression systems specify nozzle types and locations based on the cooking appliance used. Given this, simply replacing an appliance can result in non-compliance and worse, fail to provide adequate protection.
Compliance is Easy with Koorsen
Clearly, the requirements for installing and operating a wet chemical fire suppression system in your commercial kitchen and ensuring its compliance after modification is a complex matter. Koorsen is here to help. Our team of NICET-certified, factory-trained engineers and technicians can help you keep not just your kitchen but your entire facility safe and secure. Contact Koorsen today to learn more.
