Key Takeaways
In this article
Kitchen fires are different because the fuel source is often hot cooking oil or fat.
Deep fat fryers are one of the most significant risks because cooking oil can reach very high temperatures and can re-ignite if it is not cooled properly. Once a fryer fire develops, applying the wrong extinguishing method can make the situation worse. Water should never be used on a cooking oil fire because it can cause violent spread of burning oil.
Other cooking equipment can also create serious risk. Griddles, ranges, broilers, woks, chargrills and similar appliances can all produce heat, grease vapour and deposits within the canopy and extraction system.
The fire risk is not limited to the cooking surface. Grease-laden vapours can collect in filters, plenums, canopies and ductwork. If a fire enters the extract system, it can spread beyond the kitchen and into hidden parts of the building. This is why a good kitchen suppression design considers the cooking appliance, the canopy/plenum and the extract ductwork, not just the visible appliance.
Common causes of commercial kitchen fires include overheating oil, failed thermostats, unattended cooking, grease build-up, poor cleaning, damaged equipment, burners overheating and hot surfaces close to fat or dirt residues.
The kitchen environment also makes manual response more difficult. Staff may be under pressure, visibility may reduce quickly, and the safest action is usually to evacuate and allow the fixed system to operate rather than attempting to fight a developed oil fire.
Wet chemical suppression is widely used for commercial cooking risks because it is specifically suited to cooking oil and fat fires.
When discharged onto burning cooking oil, the wet chemical agent reacts with the hot fat in a process known as saponification. This creates a soapy layer over the surface, helping to smother the fire, cool the oil and reduce the risk of re-ignition.
This is very different from simply “putting liquid onto a fire”. The agent, nozzle placement, discharge pattern and coverage all matter. A system that does not apply the agent correctly to the hazard may fail to control the fire.
A commercial kitchen suppression system will normally include a cylinder containing wet chemical agent, pipework, discharge nozzles, detection, manual actuation and system monitoring. The design should be matched to the appliances, canopy, plenum and duct arrangement.
Astro uses pre-engineered kitchen suppression systems such as Jactone PAFSS KitchenGuard, which is designed for catering equipment and certified to LPS 1223. There are other recognised systems in the market, and some brand names are well known within commercial catering, but the key issue is not the brand name alone. The system must be approved, suitable for the risk, correctly designed, installed by competent trained engineers and maintained properly throughout its life.
LPS 1223 is an important approval standard for fixed fire extinguishing systems for catering equipment. It provides a recognised route for testing, certification and listing of kitchen fire suppression systems.
For building owners, facilities managers and insurers, LPS 1223 matters because it gives confidence that the system has been tested for the type of commercial cooking risks it is intended to protect.
The important point is that a kitchen suppression system should not be a collection of generic parts assembled on site. It should be a properly engineered system installed within its tested and approved limits. The system manual, nozzle positions, pipework limits, detection arrangement, cylinder size and appliance coverage must all be followed.
That is especially important when kitchens change. If a fryer is replaced, a griddle is added, the canopy is extended or the cooking line is rearranged, the existing suppression system may no longer match the hazard it was designed to protect.
Kitchen suppression systems are designed to operate automatically and manually.
Automatic operation normally occurs through heat or flame detection positioned around the cooking risk and extraction path. In systems such as PAFSS KitchenGuard, pressurised detection tubing can be located close to the identified fire risk. When the tube is exposed to sufficient heat or flame, it bursts and depressurises, causing the cylinder valve to open and release extinguishing agent through the discharge pipework and nozzles.
Manual activation is also important. Kitchen staff should have a clearly accessible means of activating the system if they discover a fire before automatic activation occurs. Manual actuators should be positioned where staff can use them safely, typically on an escape route rather than directly on the cooking equipment.
Some systems may also include monitoring for system discharge, low pressure or isolation status. Monitoring signals can be connected to local alarms, the building fire alarm system, or used to initiate shutdown of kitchen equipment or extraction where appropriate.
The important point is that kitchen staff need to understand what the system does, how to activate it manually, and what to do after it operates.
Correct coverage is where many kitchen suppression installations succeed or fail.
A kitchen fire suppression system should be designed around the actual cooking line. It is not enough to install a cylinder and a few nozzles above the general area. The nozzles must be selected and positioned so the agent reaches the hazard effectively.
The system may need to protect:
The exact arrangement depends on the system approval, the manufacturer’s manual, the appliance dimensions and the canopy/extract layout.
In the KitchenGuard manual, the system selection information makes clear that nozzles are required for the appliance, plenum and duct, with different pre-engineered modules available depending on the required coverage. The manual also notes that fryers are treated as a worst-case catering hazard, while other appliances such as griddles, ranges, broilers and woks may be protected within the system limits.
This is why survey and design matter. A system designed for one kitchen layout cannot be assumed suitable after the kitchen is altered.
A kitchen suppression system should not operate in isolation from the cooking equipment.
When the system discharges, the heat source should be shut down. This may mean shutting off gas, electricity or both, depending on the appliances and installation. If fuel or heat continues after discharge, the risk of re-ignition increases.
Extraction strategy also needs consideration. In some designs, extraction may continue to remove smoke and gases. In others, shutdown may be part of the wider cause-and-effect. The correct approach depends on the system design, manufacturer guidance, kitchen layout and fire strategy.
The system may also interface with:
These interfaces should be tested and documented. A suppression system that discharges correctly but leaves the gas supply active, fails to alert the building, or is not understood by staff is not a properly managed system.
Manual activation is a key part of kitchen fire protection.
Kitchen staff should know where the manual actuator is, when to use it and what to do after activation. It should be positioned so it can be reached safely, normally on the route out of the kitchen rather than above or beside the cooking appliance.
Training should cover the basics in plain language. Staff should understand that the suppression system is there to control cooking equipment fires, that they should never use water on a burning oil fire, that they should activate the system if safe to do so, and that evacuation and calling the fire and rescue service remain essential.
They should also understand that once the system has discharged, the kitchen cannot simply resume operation. The system will need to be cleaned, recharged, recommissioned and the appliances inspected before they are brought back into use.
A kitchen suppression system is only as good as the people managing it. Staff who do not know what the manual actuator does may lose valuable time during an incident.
Kitchen suppression systems operate in harsh conditions. Heat, grease, cleaning chemicals, steam, vibration and kitchen activity can all affect system condition.
The responsible person should ensure the system is visually checked and professionally maintained. For PAFSS KitchenGuard, the manual states that the responsible person should carry out regular visual inspections at least monthly, checking matters such as operating instructions, valve position, damage or missing parts, pressure gauge/indicator condition, manual actuator access, cylinder locking screw condition and whether catering equipment has changed since installation.
Professional maintenance is also essential. The KitchenGuard manual identifies basic service, extended service and overhaul intervals, including 12-monthly basic service, extended service every 4 years and overhaul every 8 years.
Maintenance should include checking the system against the current kitchen layout. If equipment has moved or been replaced, nozzle alignment and coverage may no longer be correct. Nozzles should be clean and unobstructed. Detection tubing should be secure and undamaged. Pipework, cylinders, actuators, pressure indicators, monitoring devices and labels should all be checked.
After any discharge, the system must be cleaned, recharged and recommissioned before cooking resumes. The KitchenGuard manual makes clear that after actuation, a general service and recharging procedure is required, and that the kitchen appliance and system must be cleaned of extinguishing agent, grease, fat, oil and dirt residue before reinstatement.
Commercial kitchen suppression is often driven as much by insurance requirements as by legislation.
Insurers understand how quickly a commercial kitchen fire can spread, especially where extract systems are involved. A restaurant, hotel, school, hospital or care facility may find that insurance conditions require suitable kitchen suppression, regular maintenance, duct cleaning, staff training and records.
Failure to maintain the system can create serious problems after a fire. If the system has not been serviced, if the kitchen layout has changed without review, if nozzles are blocked, or if the system is isolated, the insurer may challenge whether reasonable precautions were taken.
For hospitality and catering businesses, the operational risk is also significant. A fire can close a kitchen immediately. Even a contained incident may result in lost trading, damaged equipment, cleaning costs, environmental health involvement and reputational damage.
A properly designed and maintained suppression system helps protect people, property, revenue and business continuity.
One of the most common problems with commercial kitchen fire suppression is that kitchens change after the original installation.
A kitchen may start with two fryers and a griddle, then later add a chargrill, wok station or additional fryer. Equipment may be moved to improve workflow. A canopy may be altered. A new appliance may sit outside the original nozzle coverage. Filters may change. Extraction may be modified.
The suppression system is sometimes forgotten during these changes.
That creates a serious risk. A system may still appear to be installed and serviced, but it may no longer protect the actual cooking hazards in the room. A nozzle aimed at an old fryer position may not protect the new fryer. A new appliance may sit outside the protected zone. A duct or plenum may be larger than the original system was designed for.
Every kitchen change should trigger a fire suppression review. This is especially important before adding or moving fryers, griddles, woks, chargrills or any appliance that uses or produces grease-laden vapours.
The most common failures are usually practical.
A system may be designed for an old kitchen layout. A manual actuator may be obstructed. Nozzles may be blocked by grease or knocked out of alignment during cleaning. Appliance changes may not have been reported to the fire protection contractor. Detection tubing may be damaged or exposed to conditions outside its intended limits. Extract protection may be incomplete. Staff may not understand how to activate the system.
Maintenance can also be treated as a paperwork exercise rather than a technical review. In reality, the engineer should be checking whether the system is still suitable for the risk, not just whether a label can be updated.
Another issue is brand confusion. Some kitchen suppression brand names are well known, and people sometimes refer to them as if they are the only option. What matters is that the selected system is approved for the application, installed by competent trained personnel, designed within its certified limits and maintained properly. Astro’s approach is to use suitable approved systems, such as PAFSS KitchenGuard, where they match the risk and client requirements.
Commercial kitchen fire suppression should start with a proper survey.
The survey should consider the cooking appliances, the canopy, the plenum, the ductwork, the fuel type, the kitchen workflow, manual actuator location, system monitoring, shutdown interfaces and maintenance access.
For new kitchens, the suppression system should be considered before the kitchen is finalised. For existing kitchens, the system should be reviewed whenever equipment changes or when there is uncertainty about coverage.
The key questions are:
Astro Fire Systems can survey, design, install and maintain commercial kitchen fire suppression systems using suitable approved wet chemical solutions, including PAFSS KitchenGuard where appropriate. We also support system reviews, kitchen layout change assessments, maintenance, discharge response and recommissioning.
A kitchen fire suppression system is not a decorative compliance item. It is a critical safety system designed to control one of the highest-risk areas in a commercial building.
When it is correctly designed, installed and maintained, it can be the difference between a contained kitchen incident and a major fire loss.
LPS 1223 - fixed fire extinguishing systems for catering equipment
BS EN 16282-7 - installation and use of fixed fire suppression systems in commercial kitchens
Manufacturer's design, installation and maintenance manual, such as PAFSS KitchenGuard
BS 5839-1:2025 - fire detection and fire alarm systems, where suppression is monitored or interfaced
BS 6173 - gas-fired catering appliances, including gas interlocks and shut-off
TR19 Grease - cleaning of kitchen extract ductwork
Regulatory Reform (Fire Safety) Order 2005 - duties of the responsible person
Insurer and LPC requirements
Site-specific survey and kitchen layout change review
Wet chemical fire suppression is a specialised fire suppression system designed specifically for commercial cooking environments and the unique fire risks associated with cooking oils, fats and grease-laden vapours. These systems are commonly installed to protect deep fat fryers, ranges, griddles, chargrills, extraction canopies and associated ductwork.
The extinguishing agent works through a process known as saponification. When discharged onto burning cooking oils or fats, the agent reacts with the fuel to create a soap-like layer across the surface. This helps suppress the flames, cool the oil and reduce the risk of re-ignition. This is particularly important because cooking oil fires can continue to re-ignite if the oil remains above its ignition temperature.
Unlike general-purpose extinguishing agents, wet chemical systems are specifically designed and tested for commercial kitchen hazards. The position of discharge nozzles, the type of cooking equipment being protected and the layout of the extraction system all form part of the system design.
In addition to extinguishing the fire, many kitchen suppression systems also incorporate functions such as fuel isolation, electrical shutdown and alarm signalling to help reduce the risk of fire spread and support the overall emergency response strategy.
The objective is not simply to extinguish the fire, but to control it quickly, prevent re-ignition and limit its spread through the cooking and extraction system.
Reviewed by David Cullis, Managing Director, Astro Fire Systems Ltd. Astro Fire Systems Ltd is BAFE certificated under SP203-1 (Fire Detection & Alarm Systems) and SP203-3 (Fixed Fire Suppression Systems).
The requirement for a commercial kitchen fire suppression system should be determined through a fire risk assessment, consideration of insurer requirements and an understanding of the cooking processes being carried out. However, many commercial kitchens containing deep fat fryers, griddles, chargrills, wok stations and other grease-producing cooking equipment are considered strong candidates for fixed suppression systems.
Commercial kitchen fires can develop rapidly and often involve cooking oils, fats and grease deposits within extraction systems. Once a fire enters the canopy or ductwork, it can spread beyond the cooking appliance and affect other areas of the building. Early intervention is therefore critical.
The Regulatory Reform (Fire Safety) Order 2005 places a legal duty on the Responsible Person to undertake a suitable and sufficient fire risk assessment and implement appropriate fire precautions to protect relevant persons from fire. In commercial kitchens involving deep fat frying, high-temperature cooking processes, open-flame cooking or significant grease extraction systems, the fire risk assessment may identify the need for fixed suppression as part of the overall fire protection strategy. In many higher-risk kitchen environments, suppression systems are considered one of the most effective methods of controlling fire at source and reducing the risk to an acceptable level.
Fixed kitchen suppression systems are designed to provide automatic protection directly at the source of the hazard and within associated extraction systems.This can significantly reduce fire damage, limit business interruption and improve the likelihood of a kitchen returning to operation following an incident.
Many insurers view kitchen suppression systems favourably and, in some cases, may require them as a condition of cover for higher-risk cooking operations.The presence of an approved suppression system can also demonstrate a proactive approach to risk management and asset protection.
For many commercial kitchens, the question is not simply whether a fire can be extinguished, but how quickly it can be controlled before it spreads through the cooking and extraction system. A properly designed suppression system helps achieve that objective whilst protecting staff, property and business continuity.
LPS 1223 is a Loss Prevention Standard developed by the Loss Prevention Certification Board (LPCB) for fixed fire suppression systems protecting commercial cooking equipment and kitchen extraction systems. The standard provides an independent approval process designed to verify that a suppression system has been tested and assessed for its intended application.
The approval process evaluates the complete suppression solution rather than simply individual components. This includes factors such as detection arrangements, extinguishing agent performance, discharge hardware, system operation and the system's ability to control fires associated with commercial cooking hazards.
For kitchen operators, building owners and insurers, LPS 1223 approval provides confidence that the system has undergone recognised testing against representative commercial kitchen fire scenarios and has demonstrated an appropriate level of performance. It helps distinguish independently approved systems from untested or non-certified solutions.
Many insurers, risk managers and fire professionals view LPCB-approved systems favourably because they provide evidence that the suppression system has been independently assessed against an established industry standard.
When selecting a commercial kitchen fire suppression system, approval to standards such as LPS 1223 can be an important factor in demonstrating that the chosen solution is suitable for protecting the specific cooking hazards present.
Following the discharge of a kitchen fire suppression system, cooking operations should normally cease until the cause of the incident has been investigated, the affected equipment has been inspected and the suppression system has been reinstated. Whilst the system is designed to control or extinguish the fire, a discharge event should be treated as a significant incident rather than a routine interruption.
The recovery process will typically include cleaning the discharged extinguishing agent from cooking appliances, canopies and surrounding surfaces, removing grease contamination and inspecting equipment for any signs of heat, fire or smoke damage. Depending on the nature of the incident, extraction systems and ductwork may also require inspection and cleaning.
The suppression system itself will normally require servicing by a competent engineer. This may include replacing or recharging agent cylinders, inspecting discharge nozzles, resetting detection and actuation components, verifying shutdown interfaces and recommissioning the system in accordance with the manufacturer's requirements.
Consideration should also be given to the cause of the fire. If cooking equipment has been modified, replaced or repositioned, or if the cooking process has changed, the suppression system may need to be reviewed to ensure that protection remains appropriate for the hazard.
Although downtime will vary depending on the size of the incident and the type of kitchen involved, most commercial kitchens should expect a period of disruption whilst the fire protection system, cooking equipment and extraction systems are returned to a safe and operational condition.
Commercial kitchen fire suppression systems should be inspected, tested and maintained in accordance with the system manufacturer's requirements, the applicable approval standard and any insurer or regulatory requirements. Whilst servicing intervals vary between manufacturers and system types, a professional inspection at least annually is commonly regarded as the minimum requirement for most installations.
Between service visits, the responsible person should carry out routine visual checks to confirm that the system remains in serviceable condition. This may include checking pressure indicators, ensuring discharge nozzles remain correctly positioned and unobstructed, verifying that manual actuation devices are accessible and confirming that cooking equipment has not been altered, relocated or replaced without assessing the impact on the suppression system.
In addition to routine annual servicing, many kitchen suppression systems include components that require inspection, testing, replacement or overhaul at specific points during the lifecycle of the system. Examples may include agent cylinders, detection components, flexible hoses, actuators, seals and other critical parts. The exact requirements will depend on the system manufacturer and the approved maintenance programme for that particular system.
Commercial kitchens are challenging environments for fire protection equipment. Heat, grease, steam, cleaning chemicals and frequent operational activity can all affect system performance over time. Regular maintenance helps ensure that the system will operate correctly if a fire occurs and that the protection remains appropriate for the cooking equipment being used.
The key principle is that maintenance should follow the manufacturer's approved servicing schedule rather than relying solely on a fixed time interval. A kitchen suppression system should be viewed as a life-safety and asset-protection system that requires ongoing inspection and maintenance throughout its operational life.
Whether you need a new system, an existing installation reviewed, or maintenance support, our engineers can help. Call 01905 964703 or request a free site survey.
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BAFE accredited fire protection specialists (SP203). Over 20 years of experience in fire suppression and detection for data centres, manufacturing, commercial and public sector clients across the UK.
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