A fire blanket is a safety device designed to extinguish small incipient (starting) fires. It consists of a sheet of fire retardant material which is placed over a fire in order to smother it (see below).
Small fire blankets, for use in kitchens and around the home, are usually made of fibreglass, and are folded in to a quick-release container for ease of storage.
Larger fire blankets, for use in laboratory and industrial situations, are often made of wool (sometimes treated with a flame retardant fluid). These blankets are usually mounted in vertical quick-release cabinets so that they can be easily pulled out and wrapped round a person whose clothes are on fire.
Some older fire blankets were made of woven asbestos fibre. This can pose a hazard during the decommissioning of old equipment.
In order for a fire to burn, all four elements of the fire tetrahedron must be present: heat, fuel, oxygen and a sustaining chemical chain reaction. A fire blanket either completely surrounds a burning object or is placed over a burning object and sealed closely to a solid surface around the fire. Whether the blanket is placed on top, or surrounding it, the job of the blanket is to cut off the oxygen supply to the fire, and put it out.
In using a fire blanket, it is important to protect the hands; the picture at the top of this page shows the correct procedure, in which the blanket is folded around the hands to protect them from the heat whilst it is applied.