The Essential Guide to CO2 Fire Extinguisher Placement

When it comes to fire safety, having the right extinguisher is only half the battle, knowing where to put it is just as important. Carbon dioxide (CO2) extinguishers are one of the most effective tools available for protecting environments where electrical equipment and flammable liquids are present. But in the wrong location, even the best extinguisher isn't effect.

If you're setting up fire safety for your workplace and wondering whether a CO2 extinguisher is required, and exactly where it should go, this guide will walk you through everything you need to know.

What Makes a CO2 Fire Extinguisher Different?

CO2 fire extinguishers work by displacing the oxygen that fire needs to burn. Unlike dry powder extinguishers, it leaves no residue after use, which makes it the preferred option in environments where sensitive equipment, documents, or surfaces need to be protected after a fire event.

In Australia, CO2 extinguishers are typically identified by a black band on the cylinder, in line with Australian Standard colour coding. The 5kg CO2 extinguisher is the most common size used in commercial and industrial settings, offering enough capacity to tackle flammable liquids(Class B) and electrical fires (Class E) without overwhelming a standard work environment.

Important to note: CO2 extinguishers are not suitable for Class A fires - combustibles like paper, wood, or textiles.

The Right Environments for CO2 Extinguishers

Server Rooms and Data Centres

Server rooms contain significant electrical equipment, and very little tolerance for water or powder-based suppression. A CO2 extinguisher can tackle an electrical fire quickly and cleanly, without destroying the equipment you're trying to protect.

Placement recommendation: mount outside the server room entry point, clearly signed, at a height accessible to all staff.

Electrical Switch Rooms and Substations

Any location with an electrical panels, switchboards, or distribution equipment is a candidate for CO2 coverage. These environments carry a real risk of Class E - electrical fires, and CO2 is one of the safest agents to deploy in these situations, as it doesn't conduct electricity and won't cause further damage to live equipment.

Commercial Kitchens (With one critical reservation)

CO2 extinguishers are suitable for kitchens where flammable liquid fires (Class B) might occur, such as deep fryer overflows or fuel-based ignition.

However, they should always be used alongside a wet chemical extinguisher in professional kitchen environments, as wet chemical is specifically rated for Class F cooking oil fires. A CO2 unit alone is not sufficient kitchen coverage under Australian Standards.

Office Environments with High Electrical Load

Open plan offices packed with workstation computers and cabling are increasingly common, and increasingly at risk. While many offices default to ABE dry powder extinguishers, those working in environments with expensive electronics or irreplaceable documents should consider CO2 as a complement to their existing coverage.

Placement recommendation: They should be positioned near, but not directly next any risk source.
If placed too close, access may be blocked during a fire.

Australian Standards: What the Regulations Say About Placement

Under AS 2444 (Portable Fire Extinguishers - Selection and Location) and the broader fire safety framework referenced in the National Construction Code (NCC), the positioning of CO2 extinguishers in a workplace must meet specific requirements:

• Travel distance, generally 10 to 20m depending on the risk/hazard classification
• Extinguishers should be visible and accessible at all times, not obstructed by equipment, furniture, or stock
• They must be within 15 metres travel distance from any point in the protected area (for Class E hazards)
• Mounting between 100mm and 1.2m from the floor, mounting height should allow the carrying handle to be no more than 1.5 metres from floor level
• Signage above the extinguisher must comply with AS 2444. A red sign with white text indicating extinguisher type
• All portable extinguishers must be inspected and serviced to AS 1851 standards - six-monthly checks at minimum

If you're unsure whether your current placement meets compliance, a qualified fire protection technician can assess and advise.

Don't Risk it: Common Placement Mistakes

Placing CO2 in enclosed, unventilated rooms without warning. CO2 displaces oxygen, in a small or enclosed space with no ventilation, even discharging a 5kg extinguisher creates a brief but real risk of oxygen depletion for anyone inside. This doesn't make CO2 dangerous in normal use, but it does mean you should ensure egress is clear and staff are trained on safe use.

Using CO2 as your only extinguisher. CO2 does not cover Class A fires. A workplace with a CO2 extinguisher and nothing else is not compliant, you'll need an ABE or water extinguishers to cover ordinary combustibles.

Storing CO2 extinguishers near heat sources. CO2 cylinders are pressurised. Avoid placement near extreme heat scources or in direct sunlight for extended periods.

Forgetting to include it in your fire warden training. The distinctive CO2 horn can be unfamiliar to staff who have only trained on powder extinguishers. Including the CO2 unit in your warden training ensures staff are properly equipped in an emergency.

How Many CO2 Extinguishers Does Your Workplace Need?

The number of extinguishers required depends on the size and risk profile of the area being covered. AS 2444 uses a formula based on floor area and hazard classification, but as a general guide:

• Low-hazard areas (offices, standard commercial): one extinguisher per 200m² of floor area
• High-hazard areas (workshops, electrical rooms): higher density, with specific units placed at each identified risk point

A fire protection specialist can assess your site and provide a compliant placement plan. For multi-storey buildings or large facilities, this isn't optional, it's a legal requirement.

Pairing Your CO2 Extinguisher with the Right Coverage

No single extinguisher type covers every risk. In most Australian workplaces, CO2 extinguishers work best as part of a layered approach:

• CO2 (Black band) - electrical equipment, flammable liquids, server rooms
• ABE Dry Powder (White band) - general-purpose coverage across Class A, B, and E fires
• Wet Chemical (Oatmeal band) - commercial kitchens and Class F cooking oil fires
• Water (Red band) - Class A fires in low-electrical-risk environments

By understanding what each unit covers, you can build effective fire protection, rather than relying on a single product to do everything. Check out our post on Fire extinguisher colour codes.

5kg CO2 Extinguisher - Why Size Matters

The 5kg CO2 extinguisher is the workhorse for commercial applications. It provides enough discharge time and suppression capacity to handle a meaningful fire event while remaining manageable for most adults to operate under stress.

A 2kg CO2 unit is often sufficient for small, enclosed risks like a home office or a single server rack, but in any commercial or industrial application, the 5kg unit offers better coverage, and meets compliance requirements

Checkpoint Group's 5kg CO2 fire extinguisher meets Australian Standards and is suitable for use across office, commercial, and light industrial environments.

Final Safety Checklist: Is a CO2 Extinguisher Right for Your Space?

Ask yourself these 3 questions:

1. Does your workplace contain electrical switchboards, server racks, or sensitive electronics?
2. Do you store or use flammable liquids on site?
3. Would residue from a dry powder extinguisher cause significant damage to equipment?

If you answered yes to any of these, a CO2 extinguisher should be part of your fire protection setup, and its placement deserves as much thought as its selection.