Which Fire Extinguisher Do I Need? | UK Guide 2026

Choosing the Right Fire Extinguisher

Choosing the right fire extinguisher depends on more than simply the size of the building.

You need to consider:

• The types of fire that could occur • The materials and equipment present • The required fire ratings • Floor area and layout • Travel distances • Specific or specialist hazards

Traditionally, different fire risks have been protected using different extinguishing media, such as water, foam, CO₂, dry powder, and wet chemical.

Modern multi-risk extinguishers such as Zenova FX provide another option, allowing several common fire risks to be covered using one extinguishing medium where appropriately specified.

This guide explains the main fire classes,

traditional extinguisher choices,

and where Zenova FX can provide an alternative.

Understanding Fire Classes

CLASS A

Solid Combustible Materials

Class A fires involve everyday combustible materials such as:

Wood • Paper • Cardboard • Textiles • Furniture

Traditional choices include water, foam, and other suitably Class A-rated extinguishers.

Zenova FX

Zenova FX extinguishers carry Class A fire ratings, making them suitable for many common combustible-material risks.

The actual Class A rating varies by model, so the required rating and number of extinguishers must still be considered.

CLASS B

Flammable Liquids

Class B fires involve flammable liquids such as:

Petrol • Diesel • Paint • Solvents

Traditional extinguisher options can include foam, CO₂, and appropriate dry powder, depending on the particular risk.

Zenova FX

Zenova FX also carries Class B fire ratings, allowing suitably rated FX models to tackle both Class A combustible materials and Class B flammable-liquid fires.

This can be particularly useful where several common fire risks exist within the same premises.

CLASS C

Flammable Gases

Class C fires involve flammable gases such as:

Propane • Butane • Methane • Natural Gas

These require particular consideration.

Where safe and practicable, the priority is normally to isolate the gas supply. Simply extinguishing the flame while gas continues to escape could create a more dangerous situation.

Zenova FX & Class C

Zenova states that the FX extinguishing agent has been tested on Class C fires, demonstrating additional capability of the extinguishing medium.

However, this should not be interpreted as meaning that Zenova FX should automatically be specified for every Class C hazard.

Class C risks should be assessed individually, taking account of the gas involved, means of isolation, and the fire risk assessment.

TESTED CAPABILITY ≠ AUTOMATIC SELECTION

Zenova FX demonstrates broad extinguishing capability, but specialist hazards still require specialist consideration.

CLASS D

Combustible Metals

Class D fires involve combustible metals, which can include:

Magnesium • Sodium • Potassium • Titanium

These are specialist fire risks.

The appropriate extinguishing agent can vary depending on the specific metal involved, so a general-purpose extinguisher should not automatically be specified for a Class D hazard.

Zenova FX & Class D

Zenova states that FX has also been tested on Class D fires.

This demonstrates another aspect of the broad capabilities of the FX extinguishing fluid, but it does not remove the need to assess a combustible-metal risk individually.

Where a significant Class D hazard exists, specialist extinguisher provision appropriate to the particular metal should be considered.

CLASS F

Cooking Oils & Fats

Class F fires involve high-temperature cooking oils and fats.

Typical risks include:

Deep-fat fryers • Vegetable oils • Animal fats • Commercial cooking equipment

Traditionally, these risks are protected using a suitably rated wet chemical extinguisher.

Zenova FX

Selected Zenova FX extinguishers also carry Class F fire ratings, providing another option where cooking-oil risks are present.

For example:

FX6L — 75F FX9L — 75F

The required Class F rating should still be determined according to the actual cooking-oil risk present.

What About Electrical Fires?

Electrical Equipment Isn't a Fire Class

Although the term “electrical fire” is commonly used, electrical equipment isn't itself a UK fire class.

Instead, consideration needs to be given to whether the extinguishing medium is appropriate for use where live electrical equipment may be involved.

Where safe and practicable, electrical equipment should be isolated from the power supply before attempting to tackle a fire.

Zenova FX & Electrical Equipment

Electrical capability is an important feature of Zenova FX.

The technical information supplied for the FX6L and FX9L states that they are:

SAFE FOR USE ON LIVE ELECTRICAL EQUIPMENT UP TO 1000V

The same technical data identifies the FX6L and FX9L as EN3-7 certified for A, B, Electrical, and F fires, with BSI Kitemark certification.

This can make Zenova FX particularly useful in general commercial environments containing a mixture of:

Combustible materials • Computers • Printers • Appliances • Electrical equipment

However, there is an important distinction.

What About Plant Rooms & Electrical Rooms?

Dedicated Electrical Risks Need Separate Consideration

Zenova FX's electrical capability does not mean that CO₂ or other electrically non-conductive extinguishers should automatically be removed from every premises.

Areas containing significant or dedicated electrical hazards should be considered separately.

Examples can include:

Switch rooms Electrical intake rooms Distribution equipment Switchgear Control equipment Plant rooms Other significant live electrical installations

For these risks, an appropriate electrically non-conductive extinguishing medium such as CO₂ may still be recommended.

CO₂ STILL HAS AN IMPORTANT ROLE

CO₂ is electrically non-conductive and leaves no extinguishing-agent residue, making it particularly useful around sensitive electrical and electronic equipment.

So while Zenova FX can potentially simplify extinguisher provision across general areas containing electrical equipment, dedicated electrical hazards should still be assessed individually.

Traditional Extinguishers vs Zenova FX

WATER

Typically Used For:

Class A

Water extinguishers are effective on ordinary combustible materials such as wood, paper, and textiles.

Best suited to: General Class A risks.

Limitation: Not a universal solution for flammable liquids, cooking oils, or dedicated electrical hazards.

FOAM

Typically Used For:

Class A & appropriate Class B risks

Foam has traditionally been used where both solid combustible materials and certain flammable-liquid risks are present.

Best suited to: Appropriate Class A/B environments.

Consideration: Suitability depends on the particular extinguisher and hazard.

CO₂

Typically Used For:

Electrical Equipment & appropriate Class B risks

CO₂ is particularly useful around electrical equipment.

Advantages

✓ Electrically non-conductive ✓ Leaves no residue ✓ Useful around sensitive equipment

CO₂ can therefore remain an important part of extinguisher provision for dedicated electrical risks, switchgear, and plant/electrical rooms.

DRY POWDER

Broad Fire-Fighting Capability

Dry powder can provide broad fire-fighting performance depending on the formulation.

However, discharge produces significant amounts of powder.

This can:

Reduce visibility Contaminate equipment Create substantial clean-up Cause disruption following discharge

For these reasons, powder may not be desirable for many indoor environments.

WET CHEMICAL

Typically Used For:

Class F

Wet chemical extinguishers are specifically associated with cooking-oil and fat fires.

They remain an established choice for commercial kitchens and deep-fat frying risks.

The Zenova FX Alternative

Multi-Risk Fire Protection

Zenova FX takes a different approach.

Rather than requiring a different extinguishing medium for every common fire risk, the FX range provides multi-risk fire-fighting capability using Zenova's FX fluid.

Zenova's supplied technical information states capability across:

A • B • C • D • ELECTRICAL • F

However, the distinction between certification/fire ratings and additional tested capability is important.

For example, Zenova's current FX6L and FX9L technical sheets specifically identify EN3-7 certification for A, B, Electrical, and F, while separately stating that the extinguishers can put out A, B, C, D, Electrical, and F fires.

We therefore recommend assessing Class C, Class D, and other specialist hazards individually, rather than treating tested capability as automatic suitability for every application.

Why Consider Zenova FX?

MULTI-RISK PROTECTION

One extinguisher range can provide protection across several common fire risks.

SIMPLER PROVISION

Where appropriately specified, Zenova FX may reduce the number of different extinguisher types required within a premises.

Important:

Fewer extinguisher types do not necessarily mean fewer extinguishers.

Minimum quantities, fire ratings, positioning, and travel distances still apply.

ELECTRICAL CAPABILITY

Selected Zenova FX models provide tested and certified electrical capability, including suitability for live electrical equipment up to 1000V according to the supplied FX6L and FX9L technical data.

CLASS F PERFORMANCE

Selected FX models provide Class F capability alongside their Class A and B ratings.

REDUCED CLEAN-UP

Zenova FX provides an alternative to traditional dry powder where powder contamination and post-discharge clean-up may be undesirable.

Which Zenova FX Do I Need?

FX500

Compact Multi-Risk Protection

3A • 15B • 15F

Compact 500ml protection suitable for smaller and portable applications.

Zenova's supplied 2025 product information also lists the FX500 as dielectrically tested.

FX2L

Compact Protection

13A • 34B

Zenova's supplied 2025 information also lists a 25F figure, but marks this as currently undergoing testing. I would therefore avoid presenting 25F as an established certified rating until updated certification is available.

The FX2L is listed as dielectrically tested.

FX6L

Commercial Multi-Risk Protection

34A • 113B • 75F

A versatile option for offices, workplaces, shops, commercial premises, and other suitable applications.

The supplied technical data confirms EN3-7 certification, BSI Kitemark certification, and suitability for live electrical equipment up to 1000V.

FX9L

Higher-Capacity Protection

43A • 183B • 75F

Designed for applications requiring greater extinguishing capacity and higher fire ratings.

The supplied technical data confirms EN3-7 certification, BSI Kitemark certification, and suitability for live electrical equipment up to 1000V.

Quick Selection Guide

Risk / Environment	Traditional Choice	Zenova FX Consideration
Class A	Water / Foam	Suitably A-rated FX
Class B	Foam / CO₂ / appropriate powder	Suitably B-rated FX
Class C	Specialist assessment	Tested FX capability — assess specifically
Class D	Specialist Class D agent	Tested FX capability — assess specifically
Class F	Wet Chemical	Suitably F-rated FX
General electrical equipment	CO₂ / suitable medium	FX may provide multi-risk protection
Dedicated electrical risk	CO₂ / suitable non-conductive medium	Assess separately
Plant / switch room	CO₂ often appropriate

Which Extinguisher for an Office?

An office commonly contains:

Paper • Furniture • Computers • Printers • Electrical appliances

Traditionally, this can result in a combination of Class A extinguishers plus CO₂.

A suitably specified Zenova FX extinguisher may provide an alternative multi-risk solution for general office areas, potentially reducing the number of different extinguisher types required.

Which Extinguisher for a Shop?

Retail premises typically contain significant Class A combustible materials alongside electrical equipment.

Depending on the stock and additional hazards present, a suitably rated Zenova FX6L or FX9L may provide broad multi-risk protection.

Which Extinguisher for a Workshop?

Workshops can contain very different hazards:

Wood • Packaging • Flammable liquids • Electrical equipment • Machinery • Gas • Metals

Zenova FX may provide useful multi-risk protection for appropriate hazards.

However, significant gas, combustible-metal, electrical or other specialist risks should be assessed separately.

Which Extinguisher for a Commercial Kitchen?

Commercial kitchens can contain:

Cooking oils • Electrical appliances • Combustible materials • Gas

Class F protection is particularly important around deep-fat fryers and significant cooking-oil risks.

Suitably F-rated Zenova FX extinguishers may provide multi-risk protection, but the required Class F rating and any gas/electrical risks should be assessed individually.

Which Extinguisher for a Plant Room?

This depends heavily on what is actually inside the plant room.

Where the primary concern is dedicated electrical equipment, switchgear or control equipment, CO₂ or another suitable electrically non-conductive extinguishing medium may remain appropriate.

Where other combustible materials or hazards are present, additional extinguisher provision may be required.

Don't select purely from the room name.

Assess the actual hazards within the room.

How Many Fire Extinguishers Do I Need?

Choosing the right type is only part of the process.

BS 5306-8:2023 also considers the required number, fire rating and positioning of extinguishers.

For general Class A provision, this includes:

✓ Floor area of each storey✓ Aggregate Class A rating✓ Minimum extinguisher quantities✓ Travel distances✓ Doors and accessibility✓ Additional specific risks

A high-rated multi-risk extinguisher does not automatically mean that one extinguisher is sufficient for an entire floor.

Want to calculate your basic provision?

[ HOW MANY FIRE EXTINGUISHERS DO I NEED? ]

Not Sure What You Need?

Every premises is different.

If you're deciding between traditional extinguishers and Zenova FX, we can help identify suitable options based on the risks, required ratings and premises.

[ GET HELP CHOOSING ]

[ SHOP FIRE EXTINGUISHERS ]

[ EXPLORE ZENOVA FX ]

Important Information

This guide provides general information and is not a substitute for a suitable and sufficient fire risk assessment or site-specific extinguisher assessment.

Extinguisher selection and positioning should take account of the risks present, applicable fire-safety requirements, relevant standards and manufacturer's instructions.

Class C, Class D, dedicated electrical risks and other specialist hazards should be assessed individually. Tested extinguisher capability should not be interpreted as automatic suitability for every application.