CO2 Carbon Dioxide Fire Extinguisher – 3.5kg

Commander™ 3.5kg CO2 Fire Extinguisher - Carbon Dioxide Type

The Commander 3.5kg CO2 fire extinguisher carries a 5B:E fire test rating and is certified to AS/NZS 1841.6. It is the size most commonly specified for commercial and light industrial electrical risk.

Specifications

• Agent: carbon dioxide (CO2)
• Capacity: 3.5kg
• Fire test rating: 5B:E
• Standard: AS/NZS 1841.6
• Dimensions: 590mm (H) x 150mm (W) x 260mm (D)
• Cylinder: Heavy duty aluminium
• Finish: epoxy coated red, UV resistant
• Handle and safety pin: stainless steel
• Valve: brass
• Model: CP35CO2
• Supplied with: wall bracket, hose and discharge horn, AS 1851 maintenance tag
• Bulk pricing applies from two units
• Warranty: 1 year

Fires It Can Handle

Class B and Class E, as stated by the 5B:E rating.

• Class B: petrol, diesel, oils, paints, solvents.
• Class E: switchboards, distribution boards, motors, UPS units, servers, workstations and machine control panels.

Carbon dioxide displaces the oxygen around the fire, then disperses. Nothing remains after discharge. ABE powder residue is corrosive and draws moisture once it settles, which turns a contained switchboard fire into a board replacement and a room that needs cleaning before anyone works in it. CO2 leaves the equipment recoverable.

How the Three CO2 Sizes Compare

• 2kg: compact. Vehicles, small plant rooms, single-cabinet risk, and anywhere wall space is tight
• 3.5kg: the general commercial size. Offices, retail, switch rooms, comms rooms, data centres
• 5kg: larger Class B volumes and heavier industrial electrical risk

AS 2444 sizes coverage by rating, not by kilograms. Compare the rating on the label first and the weight second.

Where Not to Use It

• Class A solid combustibles: CO2 has no cooling effect, so the material reignites
• Class C combustible gases
• Class D combustible metals
• Class F cooking oils and fats: the discharge splashes burning oil
• Outdoors or in strong draughts: the gas disperses before it smothers

Safety in Use

• Oxygen displacement. In a small, sealed or poorly ventilated room, discharge creates an asphyxiation risk for the operator. Evacuate and ventilate after use.
• Cold burn. The horn and discharge reach extremely low temperatures. Operators hold the handle, never the horn.
• Thermal shock. The rapid cooling can affect energised components. Isolate the supply first where it is safe to do so.

Cover these in operator and warden training.

How to Identify a CO2 Extinguisher

Red body with a black band. The horn on the end of the hose separates it on sight from powder and foam units. Full breakdown in our fire extinguisher colour code guide.

Mounting and Placement

Under AS 2444:

• Base at least 100mm clear of the floor
• Top of the handle no higher than 1,200mm
• Positioned between 2 and 20 metres from a switchboard or identified electrical hazard, close enough to reach and far enough that the hazard doesn't block access
• Smaller units cannot be combined to substitute for one unit of the required rating

Our CO2 placement guide covers travel distances and unit counts by hazard classification. Type selection across the whole site can be found in our AS 2444 selection guide.

Signage Requirements

AS 2444 requires an identification sign above each extinguisher, mounted at 2 to 2.5 metres so the type and its fire classes are readable on approach. An extinguisher without a compliant sign fails the placement check regardless of the unit's own certification.

• CO2 identification sign
• CO2 sign kit, identification sign plus location sign

Servicing and Maintenance

Under AS 1851-2012:

• Six-monthly inspection by a competent person
• Yearly detailed service, including signage, location and bracket check
• Hydrostatic pressure test at five years

CO2 units carry no pressure gauge, so the technician verifies charge by weighing the cylinder against its stamped tare. A unit that has lost gas looks identical to a full one on the wall. Any extinguisher that has been discharged, even partly, requires service immediately rather than at the next scheduled visit. Intervals and record-keeping detail in our fire testing intervals guide. Manufacture sits under the ACCC mandatory standard for portable non-aerosol fire extinguishers.

Coverage Calculations and Bulk Orders

We supply, install and position first-responder fire equipment against AS 2444 for construction, industrial and commercial sites across Australia. Call 1800 273 473 or see the full Commander fire extinguisher range.