Fire class · US
Class K: cooking oils and fats (US)
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’
Cooking oils and fats in appliances.
United States (NFPA 10 classes)
Fires in cooking appliances that involve combustible cooking media (vegetable or animal oils and fats).
National Fire Protection Association (NFPA), Fire Extinguisher Ratings (NFPA Today blog, Brian O’Connor), table of classesFires involving combustible cooking fluids such as oils and fats.
US Occupational Safety and Health Administration (OSHA), eTool: Evacuation Plans and Procedures, Portable Fire Extinguishers, Extinguisher Basics, Fire classes
Extinguishers the guidance names for Class K
Extinguishers the guidance says not to use on it
- Carbon dioxide (CO2):
Do 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
Reading the letter
- The UK and European letter for the same kind of fire is F.
Do 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 extinguishersClass K fire extinguishers are required by NFPA 10 to be installed within 30 ft (9 m) of any areas with a potential for Class K fires.
National Fire Protection Association (NFPA), What Is a Class K Fire Extinguisher? (NFPA Today blog, Brian O’Connor), ‘Where should I install Class K fire extinguishers?’Note that there are no numerical components for Class K ratings of extinguishers like there are with Class A or B fire extinguishers since they are only tested to a single fire size (see fire testing paragraph below).
National Fire Protection Association (NFPA), What Is a Class K Fire Extinguisher? (NFPA Today blog, Brian O’Connor), ‘What is a Class K fire extinguisher?’
Other fire classes
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.
- National Fire Protection Association (NFPA): Fire Extinguisher Ratings (NFPA Today blog, Brian O’Connor) (26 August 2022). Quoted here: table of classes. 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: Fire classes; Class K extinguishers. www.osha.gov 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.
- National Fire Protection Association (NFPA): What Is a Class K Fire Extinguisher? (NFPA Today blog, Brian O’Connor) (12 August 2024). Quoted here: ‘Where should I install Class K fire extinguishers?’; ‘What is a Class K fire extinguisher?’. www.nfpa.org Checked 2026-09-29.