Estimated reading time: 7 minutes  

How the UK fire classification system works

Fire classes exist for one reason: to match the suppression agent to the fuel. Apply the wrong agent and you risk making the fire worse, or simply doing nothing useful at all. In the UK, fire classes follow the European standard EN 2, which organises fires by fuel type. Understanding how fire extinguisher types map to each class is the starting point for any sound fire protection plan.

The table below sets out the full classification system at a glance.

There’s no Class E in the UK system. Electrical hazards aren’t a separate fire class; certain extinguisher types carry a specific safety rating for use near live equipment instead. Getting classes, colour coding, rating, location and maintenance right across your premises is a compliance requirement. If you’re uncertain which extinguishers belong where, a fire risk assessment will give you a precise, site-specific answer.  

Class D fire materials: which metals carry the highest risk?

The class D fire definition comes down to the fuel: a combustible metal. These are metals that can ignite and sustain a fire, particularly when they’re present as fine particles such as powder, swarf or thin shavings. Heat, air and moisture all play a role. And that last factor is where class D fires become especially dangerous; many combustible metals react violently with water, which is why the standard fire-fighting instinct can make things dramatically worse.

So what causes class D fires? Most incidents trace back to two or three contributing factors working together: metal dust and swarf accumulating in processing areas, friction and heat generated by machining or grinding operations, and inadequate storage of reactive metals near moisture or ignition sources. Understanding definition, causes and examples of class D fire materials helps you assess your specific risk before an incident occurs.

The metals most commonly involved in UK industrial settings include:

• Magnesium: Widely used in aerospace, automotive and medical device manufacturing. Magnesium swarf and powder are highly flammable. The most frequent example of class D fire in UK industry involves magnesium machining operations where fine particles build up around equipment.
• Sodium and potassium: Both react with moisture in the air and can self-ignite. Contact with water causes a violent chemical reaction.
• Titanium: Used in aerospace and precision engineering applications. Titanium dust ignites at relatively low temperatures and burns with intense, sustained heat.
• Aluminium powder: A class D fire example that appears in manufacturing, pyrotechnics and additive manufacturing environments.
• Pure lithium: A combustible metal in raw form. This is distinct from lithium-ion batteries, which behave differently entirely and are covered separately later in this guide.
• Zirconium: Present in specialist industrial and nuclear applications.

Preventing a class D fire starts well before any ignition event. Regular cleaning schedules, proper ventilation and controlled metal storage are the practical measures that reduce risk at source. They’re also far less costly than dealing with the consequences.

Class D fire colour and class D fire symbol: how to spot the right extinguisher

All UK fire extinguishers share a red cylinder body. The colour coding refers to the panel or band on the extinguisher, identifying the suppression agent inside. It’s a quick visual system designed to work under pressure, in an emergency, when there’s no time to read a full label.

Reading the full label matters more than checking the band colour alone. A trained eye can spot the difference quickly. An untrained one under pressure cannot. That’s an argument for clear signage and regular staff familiarisation, not just correct product selection.

Where class D extinguishers belong and how to use them

A class D fire extinguisher is used exclusively on combustible metal fires. It has no application on Class A, B, C or F fires. Using it elsewhere won’t give you effective suppression; it’s simply the wrong tool.

Sites where you’d typically expect to find a class D extinguisher: metal machining and grinding workshops, aerospace and automotive manufacturing facilities, university or commercial research laboratories handling reactive metals, pharmaceutical production environments and additive manufacturing sites using metal powders. These are environments where combustible metals are processed, stored or machined as a core part of daily operations.

How to use a class D fire extinguisher: step-by-step

Knowing how to identify and extinguish class D fires in these settings is part of a broader emergency response plan, and it hinges on the people on the ground. Anyone working around combustible metals needs specific training, because the instinctive response (grabbing the nearest extinguisher or reaching for water) can transform a manageable fire into a serious incident.

On how to use a class D fire extinguisher: operate from the distance stated on the label. Apply the powder gently, with a steady side-to-side motion to build coverage across the burning material. The key is control, not force. Once the fire appears to be out, leave the powder layer undisturbed until you’re certain the metal has fully cooled; reignition is a real risk, and disturbing the layer too soon can restart the fire.

After any metal fire incident, call the fire service, even if you believe the fire is out. That’s best practice for incident management, not overcaution.

Why water makes a class D fire worse, not better

No. Water must never be used on a class D fire. This is one of the key aspects of class D fires that separates them from almost every other fire type, and it’s the aspect that causes the most harm when misunderstood.

Many combustible metals react violently with water. Sodium and potassium generate hydrogen gas on contact with water and can ignite explosively. A magnesium fire fed with water becomes more intense. What looks like a sensible intervention can rapidly turn a contained incident into something far more dangerous.

Only an appropriate class D agent should be used. Knowing how to detect and extinguish a class D fire (combustible metals) correctly, with the right equipment already in place, is what separates a controlled incident from a serious injury.

If you don’t have a suitable class D extinguisher and the fire is still small, evacuate, close doors behind you and call 999. Don’t improvise. How to extinguish a class D fire safely depends entirely on having the right product in place before an incident occurs.

Class D vs lithium-ion fires: two hazards, two different solutions

This is a genuinely common source of confusion, and it has real consequences for equipment selection.

Pure lithium is a combustible metal and falls under Class D. Lithium-ion batteries, by contrast, don’t burn metallic lithium. They undergo thermal runaway: a self-sustaining chain reaction where heat builds inside the cell, causing it to vent, catch fire and potentially explode. The chemistry is different, the behaviour is different and the correct suppression method is different.

Lithium-ion battery fires sit outside the EN 2 classification system as a distinct hazard category. They’re not class D fires. Water mist extinguishers are widely recommended for lithium-ion incidents because they cool cells rapidly and reduce the risk of reignition. Our E-Series water mist range is worth considering if your site has significant battery storage or EV charging infrastructure.

So what extinguisher should you use on Class D fires? A class D specialist dry powder extinguisher, matched to the specific metals on your site. For lithium-ion battery fires, the answer is a water mist extinguisher. Getting this distinction right is central to understanding causes, risks and how to tackle them across different types of premises.

Class D fires explained clearly is what this guide set out to do. If you need help choosing the right equipment for your specific situation or site, contact us here.  

Reading time: 7 minutes  

A pan of oil takes minutes to go from safely heating to violently ablaze. What is a Class F fire? Class F fires are among the fastest-escalating hazards in any kitchen, and the instinct most people have when a fire starts, reaching for water, is exactly the wrong response. That mistake has caused more injuries than the fire itself. This guide covers class F fire explained from the ground up. You’ll learn how to identify and extinguish class F fires safely and which wet chemical fire extinguishers you need close to hand. Whether you manage a commercial kitchen or simply want to be prepared at home, you’ll find practical guidance here that could make a real difference.  

Why Fire Classifications Matter in the UK

Before getting into class F, it helps to understand the bigger picture.

The Class F Fire Rating: What the Label Tells You

Fire extinguisher class ratings appear on the body of every extinguisher. For wet chemical extinguishers designed for cooking fires, you’ll see a fire extinguisher class F rating alongside a number. A 25F rating means the extinguisher was tested against a smaller test fire than a 75F model. Understanding these ratings helps you match the right product to the scale of your kitchen hazard, and that’s a decision worth making before you ever need it.

A Quick Guide to UK Fire Classes

How many classifications of fire are there? In the UK, five main classes exist under BS EN 2, covering the range of fuels most likely to be encountered in a fire. Each of these classes of fire requires specific extinguishing methods, which is exactly why fire extinguisher types and uses vary as much as they do.

Electrical fires sit outside this classification in the European system. Instead, individual extinguishers are tested and labelled for safe use near live electrical equipment.

It’s worth noting that the types of fire extinguisher available in the UK broadly map onto these classes. What works on a timber fire can be dangerous on a cooking oil fire. And that’s not an overstatement. With that context in place, let’s look at what makes class F fires so distinct.

Why Class F Fires Are Especially Dangerous

The key aspects of class F fires aren’t always obvious until you understand what’s happening at a chemical level.

These fires don’t behave like other kitchen fires. For one thing, they can reignite after appearing to be out, because the oil beneath the surface stays extremely hot long after visible flames are gone. For another, water turns to steam on contact with burning oil at those temperatures, projecting burning droplets outward in a violent reaction. Class F fires usually occur in kitchens. From restaurants to domestic hobs, the physics are the same wherever they start.

High-Risk Cooking Scenarios to Watch for

Class F fires that are caused by the ignition of cooking oils and fats share a consistent root cause: uncontrolled heat, usually combined with inattention.

A type F fire can start quickly and spread in seconds. Recognising these conditions is the first practical step toward preventing a class F fire, so it’s worth taking a moment to ask whether any of these scenarios apply to your kitchen right now.  

How Class F Fire Extinguishers Work

Understanding how class F fire extinguishers work helps explain why no other extinguisher type is a viable alternative.

Wet chemical extinguishers discharge a potassium solution through a long lance applicator. The lance lets you apply the agent from a safe distance. The chemical cools the burning oil rapidly, and it reacts with the surface through a process called saponification, forming a soapy layer that seals the oil and stops it reigniting. That reignition risk is the critical issue. CO2 extinguishers can disturb the burning surface and spread the fire. Foam and powder extinguishers aren’t rated for class F. Wet chemical extinguishers are the only correct extinguishing methods for cooking oil fires.

When to Leave It to the Fire Service

If the fire extends beyond a single pan, or if there’s any doubt about your safety, leave. No property is worth your safety, and class F fires escalate faster than most people expect.

Class F Fire vs Class K: Clearing Up the Confusion

Class F fire vs class K is a common source of confusion, particularly for businesses sourcing equipment internationally. Class K is the North American equivalent of class F, used in the US and Canada under NFPA standards. Both cover cooking oils and fats, but they’re tested and certified to different standards. In the UK, always look for a class F rating on the extinguisher label.

Choosing the Right Size Class F Fire Extinguisher

The right class F fire extinguishers for your setting depend on the scale of cooking. A 2-litre wet chemical model suits a smaller kitchen. A 6-litre model is standard for a commercial kitchen with a full deep fat fryer setup. The F number on the label tells you the size of the test fire it was rated against: a higher number means greater capacity.

If you’re not sure which size fits your kitchen, we’re happy to help you work that out.

Class F Fire Resistance: What Kitchen Surfaces Can’t Protect Against

When people search for class F fire resistance, they’re usually asking whether standard kitchen materials can withstand a class F fire. The short answer: not reliably. Class F fires burn at extreme temperatures. Steel surfaces conduct heat rapidly, and plastic components in kitchen equipment can degrade quickly. This is exactly why a class F cooking oil fire extinguisher positioned within reach of the cooking area isn’t an exercise in ticking boxes. It’s a genuine safety requirement.

We stock a range of class F fire extinguishers for both domestic and commercial kitchens, with options at every capacity.

Ionisation smoke alarms have been a household staple for decades, but the technology is being phased out and replaced with something better. Many people have one on their ceiling right now and have never given it much thought, but with British Standards no longer recommending them for new installations, it’s worth knowing where things stand. Whether you want to understand how they work or how they compare to modern optical alarms, this guide covers it all.  

Ionisation smoke alarms are one of the oldest forms of smoke detection technology still found in UK homes. For decades they were the standard as they were cheap to produce and widely available. You’ll still find them in plenty of properties built or fitted out before the mid-2010s.

The name comes from the science behind them. Ionisation is the process of electrically charging particles in the air and that’s exactly what happens inside the alarm’s detection chamber. A tiny amount of radioactive material creates a small but steady electrical current by ionising the surrounding air. When smoke enters the chamber, it interrupts that current and triggers the alert. It’s a surprisingly simple bit of physics when you break it down.

That detection method made ionisation alarms particularly good at picking up fast-flaming fires: the kind that spread quickly and produce relatively little visible smoke in the early stages. Think of a fire that starts from paper or dry wood, rather than a smouldering sofa cushion.

Inside every ionisation smoke alarm sits a tiny amount of a radioactive element called Americium-241. This material ionises the air inside a small detection chamber, creating a continuous low-level electrical current between two charged plates.

When smoke enters the chamber, it disrupts that current. The alarm detects the interruption and triggers the alert.

The amount of radioactive material involved is minute and there’s not enough to pose any health risk during normal use, but it’s the presence of Americium-241 that’s now causing the whole category to be wound down.

Are Ionisation Smoke Alarms Still Legal in the UK?

Yes, for now. Ionisation smoke alarms have not been banned in the UK, so if you have them installed they are not illegal. That said, BS 5839-6 no longer recommends them for new installations, and the NFCC advises replacing them with optical alarms when they reach the end of their service life.

Do Ionisation Smoke Alarms Still Work?

If yours is within its service life (typically around 10 years from the manufacture date, though always check your specific model), it will still detect fire. Where a working ionisation alarm is in a suitable location, away from kitchens and bathrooms, it will continue to provide some protection. Replacing it with an optical alarm when it expires is still the right move.

Here’s a clear comparison between ionisation and optical smoke alarms:

The key practical difference is what each alarm is best at detecting. Ionisation alarms react quickly to fast-flaming fires with smaller smoke particles. Optical alarms, also called photoelectric alarms, are better at picking up the heavier, larger particles that come from slow smouldering fires, which are actually more common in domestic settings. Think of a cigarette left on a sofa, or a cable overheating behind a piece of furniture.

Optical alarms are also significantly less likely to sound a false alarm when you’ve left toast on a little too long, which is probably the single most irritating thing about ionisation alarms for anyone who has ever lived with one.

The technology behind optical alarms has advanced to the point where they now perform at least as well as ionisation alarms across most fire types, and in many situations better. That’s a big part of why the industry has moved on.

This is where people get understandably confused, so let’s be clear.

• For households: Many local authorities would prefer you remove the battery and take the unit to your local household waste recycling centre (HWRC). It’s worth checking what your council recommends before you do anything.
• For businesses: This is where it gets more serious. Business customers cannot dispose of ionisation smoke alarms with normal commercial refuse. They need to be taken to an appropriate recycling facility, and in larger quantities, returned to the manufacturer or handled by a specialist radioactive waste company. Fines from the Environment Agency have previously been issued for improper disposal, so it’s not worth cutting corners.

One thing you should never do is dismantle or attempt to open an ionisation smoke alarm. The radioactive source inside is safely shielded during normal use, but tampering with the device could expose the Americium-241 material. Leave it intact.

When in doubt, your local council website is usually the quickest place to find specific guidance for your area.

Never use water extinguishers on flammable liquids fires. They’ll cause the burning liquid to spread rapidly and can create an explosion hazard. Water and flammable liquids simply don’t mix, so the fuel floats on the water’s surface and spreads the flames across a wider area. For Class B fires involving petrol, oil, paint or other flammable liquids, you need extinguishers specifically designed for this fire class: foam, powder, CO2 or water mist.

Disclaimer: This guide provides general information about fire extinguisher selection for flammable liquids fires and is intended for educational purposes only. It doesn’t replace professional fire safety training, a comprehensive fire risk assessment or adherence to current UK fire safety legislation. Always consult with qualified fire safety professionals to ensure your premises have appropriate fire safety equipment and that your staff receive proper training in its use.  

Class B fires are classified under the European fire classification system used in the UK as fires involving flammable liquids or liquefiable solids that can ignite and burn readily.

Common examples? Petrol, diesel fuel, heating oil, cooking oils, paint thinners, solvents, methylated spirits, white spirit and various alcohols. You’ll find Class B fires in numerous settings: domestic garages and kitchens, industrial facilities, vehicle maintenance workshops and anywhere people store flammable liquids.

Flammable liquids fires behave very differently from solid combustible fires. The fuel source moves and spreads rapidly across surfaces. When a flammable liquid ignites, the fire burns at the liquid’s surface where the vapours meet oxygen. This creates a pool fire with intense heat and often thick black smoke. These fires escalate quickly if you don’t address them with the correct extinguishing agent.

We use a standardised colour-coding system in the UK. Extinguishers have a red body with a coloured label or panel indicating the extinguishing agent type:

• Foam: cream-coloured label
• Powder: blue label
• CO2: black label
• Water mist: white label with specific markings
• Standard water: red label (clearly marked as unsuitable for flammable liquids fires)

Most extinguishers also include clear warnings about which fire types they should NOT be used on. Water extinguishers prominently display warnings against use on flammable liquids.

But here’s the thing: proper signage is essential for quick identification during emergencies when stress levels are high and decision-making time is limited. Mark fire extinguisher locations with photoluminescent or illuminated signs. Ideally, your fire safety signage should include simple guidance on extinguisher selection.

Regular training ensures that building occupants can quickly identify the appropriate extinguisher type, understand the colour-coding system and make safe decisions when confronted with different types of fires.  

Estimated reading time: 8 minutes

Choosing the right fire extinguisher is more complex than most people realise. You’re weighing up different types, understanding fire classifications and matching the correct extinguisher to your environment. This guide provides practical guidance to help you navigate the fire extinguisher market with confidence, avoid costly mistakes and make decisions that could save lives and property.  

Making the right choice requires a systematic evaluation of your environment and fire risks. Use this framework to identify the most suitable extinguisher type for your needs:  

Understanding each extinguisher type reveals their strengths and limitations.

One consideration cuts across almost every environment on this list. Lithium-ion batteries are now everywhere: laptops, tablets, smartphones, power tools, e-bikes and scooters. When these batteries fail, they can enter thermal runaway: a self-sustaining reaction that generates intense heat and is notoriously difficult to extinguish with a standard unit. Wherever lithium-ion devices are regularly charged or stored, a specialist lithium-ion extinguisher must be considered.  

• Portable fire extinguishers form the foundation of fire safety. But several alternatives address specific challenges.
• Fire blankets provide an essential complement in kitchens. They smother small pan fires and provide wrap-around protection for clothing fires. They lack the range and power of extinguishers for larger incidents though.
• Automatic extinguishers suit unmanned areas: engine compartments, electrical cabinets and server racks. They activate when temperature thresholds are exceeded without human intervention.
• Wheeled extinguishers serve industrial premises, warehouses and car parks where fire loads are substantial. These heavy-duty units typically range from 25kg to 50kg, though larger capacity units are available for high-risk applications. They provide extended discharge times and greater firefighting capacity than portable units.

• Lithium-ion extinguishers represent new technology. They use Aqueous Vermiculite Dispersion (AVD) to cool battery fires and control thermal runaway. Essential for premises with electric vehicles, e-bikes or significant battery storage.
• Fire suppression systems provide automatic protection for commercial kitchens, computer rooms and industrial processes. They detect and suppress fires before they spread.
• Stainless steel fire extinguishers combine full functionality with premium aesthetics. They blend into modern offices and hospitality environments and offer complete corrosion resistance.

For landlords managing multiple properties, service-free P50 extinguishers eliminate the administrative burden and cost of coordinating annual maintenance visits across numerous sites.

Fixed installation systems using clean agent technology suit environments where water or powder damage would be catastrophic: museums, archives and telecommunications facilities.

We’ve established ourselves as the UK’s leading fire safety provider through an unwavering commitment to customer satisfaction, environmental responsibility and technical expertise. With ISO9001 certification, BAFE-certified engineers and membership in the Fire Industry Association, we deliver comprehensive fire safety solutions backed by award-winning customer service.

Our specialist team provides fire risk assessments, free test reminders, and log books. Our 100% renewable electricity operations and innovative service-free extinguisher range demonstrate genuine environmental stewardship. Whether you need a single smoke alarm or a nationwide contract, we combine competitive pricing with technical knowledge that’s secured partnerships with major institutions including the Church of England.

For personalised guidance on selecting the optimal fire extinguishers for your specific needs, contact our expert team. We’ll ensure your fire safety provisions meet both legal requirements and best practice standards.  

Estimated reading time: 6 minutes

Water mist extinguishers use de-ionised water and microscopic droplets to tackle multiple fire types. They’re ideal for offices, schools and homes where you want minimal cleanup and environmental safety. Traditional extinguishers (foam, powder, CO2 and standard water units) have protected UK properties for decades. Each one specialises in specific fire classes, but you’ll often need multiple units for full coverage.

The key difference? Water mist extinguishers handle Class A, B, C and small F fires plus electrical equipment in a single unit with zero toxic residue. Traditional extinguishers typically require you to pair multiple types, and some contain harmful PFAS chemicals or create messy cleanup challenges.

Water Mist Extinguisher Strengths  

Traditional Extinguisher Strengths  

Impact on Your Fire Safety Strategy

For Water Mist Extinguishers:

• Simplify compliance by reducing the number of extinguisher types you need on premises
• Lower long-term costs with service-free P50 models (no annual servicing for 10 years)
• Protect property and equipment from water damage during fire suppression
• Support environmental sustainability commitments and eliminate PFAS exposure
• Provide safer fire protection in areas with vulnerable populations

For Traditional Extinguishers:

• Maintain established fire safety protocols familiar to trained personnel
• Access specialist protection for high-risk environments (large commercial kitchens, outdoor storage)
• Leverage lower initial investment for basic fire coverage
• Use proven solutions accepted by all insurance providers

Not Sure Which Extinguisher Is Right for Your Property?

Every building has different fire risks, and choosing between water mist and traditional extinguishers isn’t always straightforward. Our fire safety specialists can assess your requirements, explain your options and recommend the most cost-effective solution for your premises.

Whether you’re replacing outdated AFFF foam units ahead of the upcoming ban, looking to cut long-term servicing costs with P50 service-free extinguishers, or simply need guidance on meeting UK fire safety regulations, we’re here to help.

Speak to our expert team today on 0800 612 6537 for instant advice. We’ll help you find the right fire protection without the guesswork.  

Estimated reading time: 8–10 minutes

Fire safety for restaurants is harder to get right than most people expect. Class F cooking oil fires behave differently to almost every other type of fire, and the wrong extinguisher won’t just fail to work. It can make things significantly worse. This guide walks you through what actually matters when choosing from our range of wet chemical fire extinguishers, so you can buy with clarity rather than guesswork.  

Not all extinguishers are built for the same job. In a commercial kitchen, choosing the wrong one isn’t just a wasted purchase. It’s a safety risk. Here’s what to check before you commit.  

The 6-litre UltraFire and the 6-litre combination bundles suit full-service restaurants, pub kitchens and hotel restaurants best. Anywhere running multiple fryers or high-volume cooking equipment. The Class F risk is highest in these environments, and 6 litres gives you the capacity to meet it.

The Britannia P50 Wet Chemical is the smart choice for restaurant groups, chains or multi-site operators. The servicing savings compound quickly when you’re managing multiple locations. It’s also worth considering if reducing waste and environmental impact matters to your business.

Running a smaller operation? The 3-litre wet chemical extinguisher suits cafes, fast food outlets and food stalls well. The 2-litre model works for even smaller settings: catering vans and compact canteens. The hazard is smaller, but you still need a Class F-rated unit. Don’t skip it.

The Safelincs Kitchen Safety Kit is a practical starting point for smaller catering environments and managed properties. Everything you need in a single purchase.

For domestic situations: a restaurant owner’s home kitchen or a home-based catering setup, the Kidde Flame-Out compact extinguisher is a lightweight aerosol option for small grease, wood and household waste fires. The Safelincs Home Safety Kit gives you broader home fire detection and suppression in one purchase.  

Most people walk straight past a fire extinguisher without a second glance. It’s only when you’re standing in front of one, needing it, that you realise you have no idea which one to grab or how to use them. This guide answers exactly that. How many different types of fire extinguishers are there? Six, and they have their uses in very different scenarios.

Here’s the thing: fire extinguishers are not interchangeable. Using the wrong type on the wrong fire can make things considerably worse, and in some cases (water on an electrical fire, for instance) genuinely dangerous. In the UK there are six different types, each built for specific fire risks. Consider this your no-nonsense guide to knowing your CO2 from your wet chemical, and why it actually matters.

At their most basic, fire extinguishers work by removing one or more elements from the fire triangle. Fire needs three things to keep burning: heat, fuel and oxygen. Take away any one of those and the fire goes out.

Every extinguisher is a pressurised cylinder containing an extinguishing agent. Pull the safety pin, squeeze the handle, and that pressure forces the agent out through a nozzle or horn. Simple enough in principle, but the agent inside determines which fires the extinguisher can tackle safely and which it should never go near.

Different types tackle the fire triangle in different ways. Some cool the fire down, while others smother it or interrupt the chemical reaction keeping it alive. That’s what makes each type distinct and why knowing the difference matters more than most people realise.

Water mist extinguishers are a modern evolution of the traditional water extinguisher and arguably the most versatile type on this list. Same red body, but the technology inside is a significant step forward. They’ve become increasingly popular in care homes, hospitals, schools and commercial kitchens, and it’s easy to see why.

How Do Water Mist Fire Extinguishers Work?

Rather than a solid jet of water, water mist extinguishers release an ultra-fine mist of microscopic droplets. This increases the surface area in contact with the fire, cooling it faster while simultaneously displacing oxygen around the flame. The droplets are so fine that the mist is safe to use around electrical equipment up to 1000V.

What Can Water Mist Fire Extinguishers Be Used On?

Water mist extinguishers handle Class A fires (solid materials) and Class F fires involving cooking oils and fats. That combination is what sets them apart from standard water extinguishers and makes them such a practical choice in environments where multiple fire risks are present. Their suitability near live electrical equipment up to 1000V makes them incredibly versatile.

Foam extinguishers are a versatile option, identifiable by their red body and cream-coloured panel. However, water mist extinguishers are generally the preferred recommendation in most environments. They offer comparable versatility without leaving any residue to clean up, and unlike foam, they won’t cause damage if deployed near food or on delicate fabrics.

Foam remains a capable choice for workshops and commercial premises where multiple fire risks are present, but if you’re looking for a single extinguisher that covers everyday risks with minimal collateral impact, water mist is usually the better answer.

What Are Foam Fire Extinguishers Used For?

Foam works by forming a blanket over the burning material, sealing off oxygen and preventing flammable vapours from escaping and re-igniting. There’s a cooling effect too, which makes them effective on two fronts at once. Think of it as smothering and cooling simultaneously, which is a combination that makes them particularly reliable on liquid fires.

What Can Foam Fire Extinguishers Be Used On?

Foam extinguishers are rated for Class A fires (solid materials) and Class B fires covering flammable liquids like petrol and paint. That dual rating is what makes them such a practical choice where both fire risks coexist.

Foam extinguishers are usually suitable for use on live electrical equipment. Look for the dielectric test symbol on the front of the extinguisher to confirm this. Like water extinguishers, they should never be used on Class F fires involving cooking fats.

CO2 extinguishers are the clean, no-mess option. They are identifiable by their red body, black panel and distinctive hard horn rather than a standard nozzle. They are the best choice for anywhere with equipment that needs protecting, such as server rooms and offices as they leave no residue or damage.

What Can CO2 Fire Extinguishers Be Used On?

CO2 works by displacing the oxygen around a fire. Carbon dioxide is heavier than air, so it floods the area and suffocates the flames. CO2 extinguishers are rated for Class B fires (flammable liquids) and are the go-to choice for electrical fires, covering server rooms, computer-filled offices and control rooms among others.

They’re not suitable for Class A fires, as without cooling the burning material, solid fuels can re-ignite once the CO2 disperses. Worth keeping in mind if your risk assessment covers both.

A note on safety

CO2 displaces oxygen for humans as well as fires. In small or enclosed spaces, ensure ventilation after use. The horn also gets extremely cold during discharge, so always grip the insulated handle to avoid cold burns.

Powder extinguishers (often called ABC or dry powder extinguishers) are the broadest spectrum type available. Common in vehicles and outdoor spaces, you can quickly identify a powder extinguisher via its red body and blue panel.

What Are Powder Fire Extinguishers Used For?

The powder interrupts the chemical chain reaction that sustains a fire, breaking the process at a molecular level. It’s a different mechanism to cooling or smothering and it’s what gives powder its unusually wide coverage.

Dry powder extinguishers handle Class A, Class B and Class C fires. Class C covers flammable gases like LPG and natural gas, making powder one of the few types suitable for gas fires. That’s why you’ll find them in industrial environments and on commercial vehicles.

The catch? Powder is messy. It obscures visibility during use and can cause breathing difficulties in enclosed spaces. Think of it as the sledgehammer of fire extinguishers: devastatingly effective, but not remotely subtle. For most indoor settings it isn’t the first choice despite its range.

With a red body and yellow panel, wet chemical extinguishers are the specialist option. If you run a commercial kitchen, they’re non-negotiable. They exist specifically to tackle a type of fire that most other extinguishers simply cannot handle safely: burning cooking oil.

What Are Wet Chemical Fire Extinguishers Used For?

Wet chemical extinguishers work in two ways at once. The potassium-based solution reacts with burning oil to create a soapy foam layer, sealing the surface and cutting off oxygen. Simultaneously it cools the oil rapidly, reducing the risk of re-ignition once the fire is out. It’s a precise solution to a genuinely hazardous fire type, such as chip pan fires and deep fat fryers.

What Can Wet Chemical Fire Extinguishers Be Used On?

Wet chemical extinguishers are rated for Class F fires (burning cooking oils and fats) which is their primary purpose. Many models also cover Class A fires, making them a practical dual-purpose choice in kitchen environments where solid material fires are also a risk.

Outside that scope, they’re not the right tool for flammable liquids, though most Class F extinguishers are suitable for use on live electrical equipment, as they are designed for use on electrical cookers. In a kitchen setting that’s rarely a problem, but it’s worth knowing the limits before you need to act on them.

As lithium-ion batteries become increasingly common in everything from electric vehicles to e-bikes, scooters, and portable electronics, a new category of extinguisher has emerged to tackle the specific hazard they present. Class L extinguishers are designed for lithium-ion cell and battery fires, where conventional agents are largely ineffective and can sometimes make the situation worse.

Lithium-ion battery fires burn at extremely high temperatures and are prone to thermal runaway, a self-sustaining reaction that can cause a battery to repeatedly re-ignite even after it appears to have been extinguished. Class L extinguishers use specialist agents formulated to cool the battery cells rapidly and suppress this process.

These extinguishers are particularly relevant anywhere lithium-ion batteries are stored, charged, or used in significant quantities, including EV charging points, e-bike storage areas, warehouses handling battery-powered equipment, and premises with large numbers of portable devices.

Not sure which type you need at a glance? This table covers all six types, the fire classes they handle and where they’re best placed. The amber entries are the ones worth paying attention to; they flag the conditions and limitations that catch people out.  

What do we do to maintain our emergency lighting? It’s a question that doesn’t get asked nearly enough. Emergency lighting maintenance is one of those things nobody prioritises until they really, really need it. The power cuts out and suddenly those glowing green exit signs are the most important things in the building. Not to mention the fact that the law requires you to maintain emergency lighting in your building, and the stakes are higher than most people realise.

Whether you are responsible for a busy office, a bustling shop, a rented property or a sprawling commercial site, this guide covers everything you need to know when it comes to properly maintaining your emergency lighting.

  💡In This Guide

• What Is Emergency Lighting?
• What Is the Purpose of Emergency Lighting?
• Where Is Emergency Lighting Required?
• How Often Should Emergency Lighting Be Tested?
• How to Test Emergency Lighting
• Who Can Test Emergency Lighting?
• What Do We Do to Maintain Our Emergency Lighting?

Emergency lighting is a battery-backed lighting system that activates automatically when the mains power supply fails. Unlike standard light fittings, these do not rely on the grid. They have their own internal power source, so when the likes of a powercut happen, people can still see where they are going.

There are two main types: escape route lighting illuminates the path people need to follow to get out safely, while standby lighting allows normal activities to continue during a power failure. This is most common in places such as hospitals or control rooms where work simply cannot stop. Most systems are either Maintained (on all the time) or non-maintained (only activating when the mains fails). The type you need depends on how your building is used.

💡Where Is Emergency Lighting Required?

Emergency lighting is required anywhere that a loss of mains lighting would put people at risk. In practice, that means most areas of most commercial buildings. The fittings are typically needed in:

• Escape routes, including corridors and stairwells
• Open plan areas where people work or gather
• Changing rooms and toilet facilities above a certain size
• Locations housing fire fighting equipment
• Areas around fire alarm call points
• Any spot containing a hazard that someone might walk into in the dark

That last one is worth thinking about carefully. A poorly lit plant room or a stairwell with an awkward turn can be seriously dangerous without adequate lighting during an emergency.

Most commercial and public buildings will need some form of it. This includes:

• Offices and retail premises
• Schools, hospitals and care homes
• Hotels and leisure facilities
• Places of worship
• HMOs and buildings with shared communal areas

If you are unsure, a professional fire risk assessment for your premises is the right way to establish your specific requirements. Standard single-occupancy homes are generally exempt, but properties with shared areas, such as blocks of flats, will almost certainly need it in common parts like corridors and stairwells.  

Emergency lighting should be tested more often than most people realise. Emergency lighting is not a fit-and-forget installation; it needs regular, documented testing to remain compliant and, more importantly, to actually work when it is needed.

BS 5266-1:2025 (the British Standard that governs emergency lighting, updated in October 2025 to replace the previous 2016 edition) sets out a clear schedule. Here is what it looks like:

The monthly test is a quick check to confirm the system activates. The annual test is the proper stress test; it runs the batteries down to their full rated duration to confirm they can sustain the system when it counts.

Some modern systems come with self-testing functionality, where each luminaire carries out its own checks automatically and logs the results. For larger sites, this can be a genuine time-saver and is well worth considering.  

Good emergency lighting maintenance comes down to a consistent process, carried out by people who know what they are looking for every single time.

Here is what a solid regime looks like in practice:

• Monthly: A short functional test confirms all luminaires and exit signs activate correctly. Results go into the log book the same day.
• Annually: A full rated discharge test is completed, batteries are assessed, any faults are repaired and the system is certified as compliant with BS 5266-1.
• Ongoing: Any faults spotted during routine checks are dealt with promptly. A dim luminaire, a cracked fitting or a failing exit sign LED should never be left for the next scheduled test. Emergency lighting faults are not the kind of thing to add to a to-do list and forget about.

It’s also worth carrying out a visual inspection as part of your regular fire safety walkround. Fittings should be clean, undamaged, unobstructed and positioned correctly. If someone has moved a cabinet in front of an exit sign, or a new partition has been put up that leaves a dark patch in an escape route, those problems need fixing outside of the formal test schedule.

Keeping Records

This deserves its own mention, because it is the part that most often gets overlooked. A testing log is not a bureaucratic formality, but your evidence of compliance. Without it you have very little to show anyone who asks.

Your log should record every test carried out: the date and time, the name of the person responsible, the outcome and any remedial actions taken. Safelincs offers free fire safety log books to help with exactly this, ready for download instantly.

A system that has not been tested, has failing batteries or leaves dark spots in an escape route is a real risk to real people. The good news is that maintaining it properly is not complicated. A clear testing schedule, a reliable log book and competent people carrying out the checks will cover the vast majority of what you need.

If you need support, whether that is sourcing the right emergency lighting fittings and luminaires, getting clarity on your legal obligations or arranging a fire risk assessment, the Safelincs team is here and genuinely happy to help. Feel free to get in touch and we’ll answer any query you may have.