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Fire class · UK/EU

Class F: cooking oils and fats (UK and Europe)

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’

F

Cooking oils and fats.

UK and Europe (BS EN 2 classes)

Extinguishers the guidance names for Class F

Extinguishers the guidance says not to use on it

  • Water: It should not be used for kitchen fires, fires caused by flammable gas and liquids as well as fires that involve electrical equipment. Surrey County Council (Surrey Fire and Rescue Service), Extinguishers and fire blankets, ‘Water Extinguishers’
  • Water: For example, a water jet extinguisher directed at the surface of burning cooking oil, will create an expulsion of the burning oil as the water is quickly converted into steam. Fire Industry Association, Fact File 99: Class F Fires, Version 1, §3 Limitations of non-class F extinguishers
  • Foam: This type of fire extinguisher should not be used for fires caused by flammable metals, kitchen fires and fires that involve electrical equipment. Surrey County Council (Surrey Fire and Rescue Service), Extinguishers and fire blankets, ‘Foam Extinguishers’
  • Foam: Conventional foam extinguishers have been proven to extinguish the flame, but the heat involved quickly destroys the foam blanket, exposing the surface of the oil, allowing re-ignition. Fire Industry Association, Fact File 99: Class F Fires, Version 1, §3 Limitations of non-class F extinguishers
  • Dry powder (ABC): This type of fire extinguisher should not be used for fires that involve electrical equipment over 1000 volts and cooking oil fires. Surrey County Council (Surrey Fire and Rescue Service), Extinguishers and fire blankets, ‘Dry Powder Extinguishers’
  • Dry powder (ABC): 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
  • Carbon dioxide (CO2): 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

Reading the letter

  • Cooking oil or fat fires have auto ignition temperatures in excess of 340°C and are very difficult to extinguish using conventional extinguishers with a Class B capability. Fire Industry Association, Fact File 99: Class F Fires, Version 1, §2 What is class F?
  • The Class F pictogram allows easy recognition for cooking oil risks. Fire Industry Association, Fact File 99: Class F Fires, Version 1, §5 Class F extinguisher standards
  • It should be noted that the rating of Class F fire extinguishers is determined by the volume of cooking oil in the test fire in accordance with Annex L of BS EN 3-7 (e.g. 5F = 5 litres; 25F = 25 litres; 40F = 40 litres; 75F = 75 litres). Fire Industry Association, Fact File 99: Class F Fires, Version 1, §7 Installation and guidance
  • The US letter for the same kind of fire is K.

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.