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CO2 Fire Extinguishers in Liverpool and the North West
CO2 (carbon dioxide) fire extinguishers are the standard specification for protecting electrical equipment, server rooms, plant rooms, and any Liverpool premises where flammable liquid fire risks exist. Unlike water or foam, CO2 leaves no residue after discharge, which makes it the only genuinely safe choice for suppressing fires around energised electrical equipment, sensitive electronics, and any environment where post-discharge cleanup would cause significant secondary damage. For offices, IT server rooms, communication rooms, plant rooms, workshops with electrical hazards, and forecourts across Merseyside, CO2 is not optional; it is the required specification for the specific fire classes it addresses.
WOSS:UK supplies, installs, and services CO2 fire extinguishers across Liverpool, the Wirral, St Helens, Knowsley, Sefton, Southport, Halton, Warrington, and Wigan. Every extinguisher we supply is manufactured to BS EN 3-7, positioned in accordance with BS 5306-8, and serviced annually per BS 5306-3 by qualified engineers producing a written certificate for your fire safety log book. We stock the two main commercial sizes (2kg and 5kg) with immediate availability across the Merseyside area, and can quote for installation, servicing, or takeover of an existing extinguisher estate from your current provider.
What CO2 extinguishers are used for
CO2 extinguishers are effective on two specific fire classes and unsuitable for others. Getting the specification right matters because using the wrong extinguisher on the wrong fire is dangerous and often makes the situation worse.
Class B fires (flammable liquids).
CO2 is highly effective on flammable liquid fires including petrol, diesel, solvents, oils, and paint thinners. The gas smothers the fire by displacing oxygen at the fire's surface and cooling the burning material. Common Liverpool applications include workshops, garages, forecourts, chemical stores, and any premises handling flammable liquids as part of the operation.
Electrical fires.
CO2 is the recognised standard for suppressing electrical fires because it is non-conductive and leaves no residue that could damage electrical equipment or create secondary hazards. Common applications include server rooms and data centres across the Liverpool Business District and Baltic Triangle, communication rooms, plant rooms with significant electrical infrastructure, IT-heavy office environments, industrial control rooms, and forecourts with fuel pump electrical systems. For any electrical fire risk, CO2 is the default specification and the majority of commercial premises across Merseyside carry CO2 for exactly this purpose
Not suitable for Class A fires
(paper, wood, textiles, plastics), because CO2 has limited cooling effect on solid combustibles and the fire will typically re-ignite once the CO2 gas disperses. Water, foam, or water-mist extinguishers are the correct choice for Class A cover.
Not suitable for Class F fires
cooking oils and fats), because CO2 can splash hot cooking oil creating additional hazard, and does not address the specific chemistry of Class F fires. Wet chemical extinguishers are the required specification for commercial kitchens.
Positioning and signage
BS 5306-8 governs where CO2 extinguishers are positioned. The general principle is that no person on the premises should have to travel more than 10 metres to reach an appropriate extinguisher for a Class B or electrical fire, which typically means one CO2 extinguisher positioned near each significant electrical hazard and each cluster of desks in an office environment. Extinguishers must be mounted at accessible height (typically top of extinguisher between 900mm and 1.5m from floor level), positioned on escape routes rather than dead-ends, and clearly signed with BS 5499-compliant safety signage identifying the extinguisher type and the fire classes it addresses.
For server rooms and plant rooms, CO2 extinguishers should be positioned at the entry to the room rather than deep inside, so the user can retrieve the extinguisher without entering an active fire zone. WOSS:UK installs extinguishers on wall brackets with fixed anti-theft mountings, provides all required signage, and produces a site layout document showing extinguisher positions for your fire safety log book.
Servicing, maintenance, and replacement
CO2 extinguishers require annual basic service under BS 5306-3, covering external condition inspection, weight verification (CO2 loss is the primary failure mode and can only be detected by weighing), seal and pin check, hose and horn condition, and label update. Unlike water, foam, and wet chemical extinguishers, CO2 does not require the 5-year extended service (internal inspection and pressure test) because the extinguisher is sealed and pressurised. However, hydraulic pressure testing is required at 10-year intervals under CO2-specific regulation.
Full replacement is typically required at approximately 20 years, though this depends on individual unit condition and any interim damage or discharge history. WOSS:UK service reports identify units approaching end-of-life so you can plan replacement rather than face unexpected failures. Our engineers replace and dispose of end-of-life extinguishers as part of the service contract, in compliance with waste regulations.
When CO2 is the right specification for your Liverpool premises
CO2 is not the correct default for every premises, but it is the correct answer for specific fire class risks that other extinguisher types cannot address safely. The commercial logic for specifying CO2 comes down to two questions: does the premises contain significant electrical fire risk, and does the premises contain flammable liquid fire risk where residue-free suppression matters? If the answer to either is yes, CO2 is essential. Common Liverpool commercial deployments include one 2kg CO2 unit per office cluster of desks with printers and IT equipment, one 5kg CO2 unit at the entrance to each server room, one 5kg unit per plant room, and one 5kg unit per electrical switch room. For workshops handling flammable liquids alongside electrical equipment, CO2 is deployed alongside foam to cover both hazards. For forecourts, chemical stores, and vehicle-adjacent commercial premises, CO2 works alongside foam and powder to provide layered fire class cover. WOSS:UK fire risk assessments across Merseyside identify the specific electrical and flammable liquid hazards in each zone of your premises and specify the correct CO2 rating and position for each, so your team never has to make an extinguisher-choice decision under pressure.
Sizes and specification
2kg CO₂ Fire Extinguisher
Our 2kg CO2 Fire Extinguisher is designed to meet your fire safety needs with unmatched reliability. Boasting a 34B fire rating, it's the perfect companion for any electrical equipment on-site, offering peace of mind in case of emergencies.
5kg CO₂ Fire Extinguisher
Our 5kg CO2 Fire Extinguisher provides reliable protection for electrical equipment and Class B fires. With a 34B fire rating, it is a dependable choice for workplaces and commercial premises, helping you stay prepared for fire emergencies.
2kg CO₂ Fire Extinguisher Lightweight
The steel alloy 2kg CO2 extinguisher is a must for most commercial premises as carbon dioxide (CO2) is the only extinguisher suitable for electrical equipment fires. Best combined with a water additive or foam extinguisher in offices and shops
10kg CO₂ Fire Extinguisher - Wheeled
The 10kg wheeled CO₂ fire extinguisher is purpose-built for environments where large-scale electrical equipment poses a fire risk. With a 144B fire rating, it provides effective suppression of flammable liquid fires and is especially suited for use around electrical systems such as industrial control panels, plant rooms, and server banks.
20kg CO₂ Fire Extinguisher - Wheeled
The 20kg CO₂ wheeled fire extinguisher is a powerful, reliable tool for environments where large electrical systems or flammable liquids pose a serious fire hazard. Whether in server halls, marine vessels, or control rooms, it offers clean, fast suppression with a 233B fire rating.
30kg CO₂ Fire Extinguisher - Wheeled
Our 30kg CO2 fire extinguisher stands on a welded trolley with large, solid wheels that can move over all sorts of terrain, whether inside or out. Refillable and easily maintained by any company, this is a one-man operated extinguisher with a 5 metre hose and a large horn with control valve for fighting large flammable liquid or electrical equipment fires.
Safety considerations for CO2 use
CO2 extinguishers require specific user awareness that other extinguisher types do not.
Discharge horn frostbite risk: The discharge horn cools substantially during use because CO2 expands rapidly from pressurised liquid to gas. Direct contact with the horn during or immediately after discharge can cause frostbite. Users should hold the extinguisher by the handle only, not the horn.
Confined space oxygen displacement: CO2 works by displacing oxygen at the fire surface. In confined spaces (small server rooms, plant rooms without ventilation) prolonged CO2 discharge can reduce oxygen levels dangerously. Users should evacuate immediately after discharge and ventilate the space before re-entry.
Noise on discharge: CO2 discharge is loud and can be startling. Staff training should include hands-on familiarity so first-use is not the first exposure to the noise and behaviour of the extinguisher.
WOSS:UK on-site fire extinguisher training across Merseyside includes practical hands-on familiarity with CO2 discharge using training-grade units, covering safe holding, discharge technique, post-discharge evacuation, and re-entry procedures.
To arrange a CO2 extinguisher survey or discuss a servicing requirement, please click on any of the buttons below
Frequently Asked Questions
What is a CO2 fire extinguisher used for?
A CO2 fire extinguisher is used for Class B (flammable liquid) fires and electrical fires. For Liverpool businesses, this typically means server rooms, plant rooms, offices with significant electronic equipment, workshops with electrical hazards, and forecourts. CO2 leaves no residue after discharge, making it the standard specification for electrical fire risk where water or foam would cause additional damage.
CO2 works by displacing oxygen at the fire surface and cooling the burning material through rapid gas expansion. Unlike water and foam extinguishers, CO2 does not conduct electricity, which means it can be used safely on live electrical equipment without creating an electrocution hazard for the user. The absence of residue is the second major advantage; server rooms, IT equipment, sensitive electronics, and any premises where post-discharge cleanup would cause significant secondary damage all benefit from CO2 cover. Common Merseyside applications include IT and data centre environments across the Liverpool Business District and Baltic Triangle, communication rooms across corporate and industrial premises, plant rooms and switchgear rooms, chemical stores and workshops handling flammable liquids, forecourts and vehicle service premises, and any general commercial premises with significant electrical hazards. CO2 is not suitable for Class A fires (paper, wood, textiles) because it has limited cooling effect on solid combustibles, or for Class F fires (cooking oils) because it can splash hot oil. Most Liverpool premises carry CO2 alongside water or foam to cover both fire class types.
What size CO2 extinguisher do I need for my Liverpool premises?
For most Liverpool commercial premises, 2kg CO2 extinguishers cover individual office areas, small server racks, and general electrical hazards, while 5kg CO2 extinguishers are specified for server rooms, plant rooms, larger electrical installations, and communication rooms. The correct size for your specific premises depends on the fire risks identified in your fire risk assessment and the BS 5306-8 selection standard applied to your building.
Sizing decisions typically consider the physical size of the area to be covered, the specific electrical or flammable liquid hazards present, the accessibility of the extinguisher position (5kg units are noticeably heavier and harder to handle for some users), and any specific insurance or licensing requirements. A typical Liverpool office would deploy 2kg CO2 extinguishers positioned near each significant electrical cluster (server racks, printer stations, IT equipment groups), with 5kg CO2 in dedicated server rooms and plant rooms. Industrial premises across Speke, Aintree, and the wider Merseyside area typically deploy 5kg units at each significant electrical hazard with 2kg units for general office and workshop cover. Larger installations may specify 10kg wheeled CO2 units for major electrical infrastructure. WOSS:UK conducts a survey visit as part of every quotation across Liverpool and the North West so we can specify the correct sizes and positions for your specific premises rather than defaulting to a template. Correct sizing matters because under-sized cover leaves genuine risk gaps and over-sized cover wastes capital and creates handling hazards.
How often should a CO2 extinguisher be serviced?
CO2 fire extinguishers in Liverpool commercial premises must be serviced annually by a competent engineer under BS 5306-3, with additional hydraulic pressure testing required at 10-year intervals. Unlike water and foam extinguishers, CO2 does not require the 5-year extended service because the extinguisher is sealed and pressurised, but the annual weight check is essential to detect any CO2 loss over time.
The annual service is a legal requirement under the Regulatory Reform (Fire Safety) Order 2005 and is a standard commercial insurance condition. Every WOSS:UK annual service visit across Merseyside covers external condition inspection, weight verification (the primary CO2 failure mode is gradual pressure loss detected only by weighing), seal and pin condition, discharge hose and horn condition, and label update confirming next service due date. Weight loss of more than 10 percent from the nominal filled weight typically indicates a leak requiring immediate attention, usually through recharge or unit replacement. Hydraulic pressure testing at 10-year intervals requires the extinguisher to be removed from service, drained, pressure-tested to the manufacturer specification, and recertified before return to service. This is more expensive than annual service and typically approaches the cost of a new unit, which is why many businesses opt for replacement at 10 years rather than pressure testing. Full replacement is typically required at approximately 20 years, though individual unit condition varies. WOSS:UK annual service reports identify units approaching hydraulic test or end-of-life so you can plan replacement rather than face unexpected costs.
Are there any safety risks with using a CO2 fire extinguisher?
Yes. CO2 fire extinguishers require specific safety awareness because of frostbite risk from the discharge horn (which cools rapidly during use), oxygen displacement risk in confined spaces, and startle response from the loud discharge noise. Every Liverpool business using CO2 extinguishers should include practical staff training so first use is not the first exposure to these characteristics.
The discharge horn frostbite risk exists because CO2 rapidly expands from pressurised liquid to gas at the point of discharge, cooling the horn to well below freezing within seconds. Direct skin contact with the horn during or immediately after discharge can cause immediate frostbite injury. Users should always hold the extinguisher by the handle, never touch the horn during or after use, and allow the horn to warm before handling. The confined space oxygen displacement risk applies to small server rooms, plant rooms, and other enclosed spaces without adequate ventilation. CO2 works by displacing oxygen at the fire surface, and prolonged discharge in a confined space can reduce oxygen levels below the concentration needed for safe breathing. Users should evacuate the room immediately after discharge, prop the door open to allow ventilation, and not re-enter until ventilation has restored normal oxygen levels. The discharge noise is startling but not dangerous. WOSS:UK fire extinguisher training across Merseyside includes practical hands-on familiarity with CO2 discharge using training-grade units so staff experience the noise, cold, and behaviour of the extinguisher in a controlled setting before facing a real fire.
Can I use a CO2 fire extinguisher on any electrical fire?
Yes, CO2 fire extinguishers are the standard specification for suppressing electrical fires in Liverpool commercial premises, and can be used safely on live electrical equipment because CO2 does not conduct electricity. However, the underlying electrical fault should be isolated as soon as safely possible, and the CO2 will only suppress the fire, not fix the electrical fault that caused it.
The safe use of CO2 on live electrical equipment is one of the defining characteristics of the extinguisher type and is why CO2 is deployed near server racks, plant rooms, communication rooms, and other electrical hazard zones across Merseyside commercial premises. Water and foam extinguishers conduct electricity and pose an electrocution risk to the user if applied to live electrical equipment; CO2 does not. However, some practical considerations apply. First, the CO2 will only suppress the immediate fire; the electrical fault that caused the fire remains active and can re-ignite once the CO2 disperses unless the power is isolated. Where safe to do so, isolating the affected circuit through the local switch or main isolator should happen alongside or immediately after CO2 discharge. Second, very high-voltage electrical fires (typically above 1,000V) may require specialist extinguisher types beyond standard commercial CO2, and specific advice should be sought as part of your fire risk assessment. Third, some sensitive electronic equipment can be damaged by rapid temperature change from CO2 discharge, so where the fire can be safely allowed to burn briefly while the electrical isolation is completed, this can sometimes preserve more equipment than immediate CO2 application. WOSS:UK fire risk assessments across Liverpool consider these factors when specifying the CO2 requirement for your premises.
