Extinguisher type · Black band
Black fire extinguisher: Carbon dioxide (CO2)
First: raise the alarm, get out, call the fire service
UK: However, if in doubt, employees should not put themselves or anyone else at risk, but simply raise the alarm, leave the premises, and call the fire and rescue service.
HM Government (GOV.UK), A guide to making your small non-domestic premises safe from fire (accessible version), section ‘Fire extinguishers’
US: If you're unsure about whether it is safe to use a fire extinguisher, and for all other situations, alert others, leave the building, and call 911 from a mobile or neighbor's phone.
US Fire Administration (FEMA), Choosing and Using Fire Extinguishers, ‘Help people decide when to use a fire extinguisher’
Black band on a red body, and a wide horn in place of a nozzle.
- Colour code
Carbon Dioxide (CO2) BLACK
London Fire Brigade (London Fire Commissioner), Fire Safety Guidance Note GN08: Hand Held Portable Firefighting Equipment, Rev 20, §4.3, colour table- UK/EU classes named for it
- Class B, Electrical
What the guidance says it is for
Carbon dioxide (CO2) (black): for liquid and electrical fires.
HM Government (GOV.UK), Fire safety risk assessment: offices and shops (accessible version), Part 1, 3.4.2, Figure 8CO2 fire extinguishers are black and are suitable for fires involving electricals and Class B liquid fires.
Avon Fire & Rescue Service, Fire extinguishers (business fire safety guidance), ‘CO2’A carbon dioxide extinguisher should also be provided to deal with fires involving electrical equipment.
HM Government (GOV.UK), A guide to making your small non-domestic premises safe from fire (accessible version), section ‘Fire extinguishers’CO2 extinguishers are mainly used for electrical fire risks and are usually the main fire extinguisher provided in computer server rooms. They also put out Class B fires.
Surrey County Council (Surrey Fire and Rescue Service), Extinguishers and fire blankets, ‘Carbon Dioxide (CO2) Extinguishers’
What the guidance says not to use it on
Do not use on metal fires.
HM Government (GOV.UK), Fire safety risk assessment: offices and shops (accessible version), Part 1, 3.4.2, Figure 8 (carbon dioxide)Carbon dioxide and powder extinguishers are effective in extinguishing the flame, but without sealing the surface of the liquid from oxygen, the oil rapidly re-ignites.
Fire Industry Association, Fact File 99: Class F Fires, Version 1, §3 Limitations of non-class F extinguishers
In the US
US extinguishers are not colour-coded by agent; read the letters on the label.
Carbon dioxide extinguishers are listed for use on Class B and Class C fires.
National Fire Protection Association (NFPA), Fire Extinguisher Types (NFPA Today blog, Brian O’Connor), ‘Carbon Dioxide type’
Not for, in US guidance
CO2 is not recommended for Class A fires because they may continue to smolder and re-ignite after the CO2 dissipates.
US Occupational Safety and Health Administration (OSHA), eTool: Evacuation Plans and Procedures, Portable Fire Extinguishers, Extinguisher Basics, Carbon dioxide extinguishersNever use CO2 extinguishers in a confined space while people are present without proper respiratory protection.
US Occupational Safety and Health Administration (OSHA), eTool: Evacuation Plans and Procedures, Portable Fire Extinguishers, Extinguisher Basics, Carbon dioxide extinguishersDo not attempt to use a Class A extinguisher containing water or CO2 on a deep fat fryer fire.
US Occupational Safety and Health Administration (OSHA), eTool: Evacuation Plans and Procedures, Portable Fire Extinguishers, Extinguisher Basics, Class K extinguishers
Also worth knowing
A 2.5 kilogram Carbon Dioxide (CO²) extinguisher is rated as a 34B.
London Fire Brigade (London Fire Commissioner), Fire Safety Guidance Note GN08: Hand Held Portable Firefighting Equipment, Rev 20, §5.2
The label is the authority
Most modern fire extinguishers are simple to use and instructions on how to use it safely are written on the extinguisher itself.
HM Government (GOV.UK), A guide to making your small non-domestic premises safe from fire (accessible version), section ‘Fire extinguishers’
Other colours
Sources
Official guidance only: UK government, UK fire and rescue services, the Fire Industry Association, NFPA, OSHA and the US Fire Administration. Words in quotation marks are theirs.
- HM Government (GOV.UK): Fire safety risk assessment: offices and shops (accessible version) (updated 12 September 2023). Quoted here: Part 1, 3.4.2, Figure 8 (carbon dioxide); Part 1, 3.4.2, Figure 8. www.gov.uk Checked 2026-09-29.
- Fire Industry Association: Fact File 99: Class F Fires, Version 1 (October 2024). Quoted here: §3 Limitations of non-class F extinguishers. www.fia.uk.com Checked 2026-09-29.
- HM Government (GOV.UK): A guide to making your small non-domestic premises safe from fire (accessible version) (updated 20 January 2025). Quoted here: section ‘Fire extinguishers’. www.gov.uk Checked 2026-09-29.
- US Fire Administration (FEMA): Choosing and Using Fire Extinguishers (page last reviewed 1 April 2023). Quoted here: ‘Help people decide when to use a fire extinguisher’. www.usfa.fema.gov Checked 2026-09-29.
- London Fire Brigade (London Fire Commissioner): Fire Safety Guidance Note GN08: Hand Held Portable Firefighting Equipment, Rev 20 (January 2025). Quoted here: §4.3, colour table; §5.2. www.london-fire.gov.uk Checked 2026-09-29.
- Avon Fire & Rescue Service: Fire extinguishers (business fire safety guidance) (page last updated 29 February 2024). Quoted here: ‘CO2’. www.avonfire.gov.uk Checked 2026-09-29.
- Surrey County Council (Surrey Fire and Rescue Service): Extinguishers and fire blankets (reviewed 24 August 2026). Quoted here: ‘Carbon Dioxide (CO2) Extinguishers’. www.surreycc.gov.uk Checked 2026-09-29.
- National Fire Protection Association (NFPA): Fire Extinguisher Types (NFPA Today blog, Brian O’Connor) (2023). Quoted here: ‘Carbon Dioxide type’. www.nfpa.org Checked 2026-09-29.
- US Occupational Safety and Health Administration (OSHA): eTool: Evacuation Plans and Procedures, Portable Fire Extinguishers, Extinguisher Basics (no date shown). Quoted here: Carbon dioxide extinguishers; Class K extinguishers. www.osha.gov Checked 2026-09-29.