A flame retardant (FR)fabric is a special kind of technical fabric that reduces/suppresses spreading of fire through it. The special feature is that its flame-retardant features reside in its composition materials and don’t depend on a coating or a finish.
Wool is naturally flame resistant and offers a greater level of fire safety than other fibers. In addition, wool does not melt, drip or stick to the skin when it burns.
Wool’s inherent fire resistance comes from its naturally high nitrogen and water content, requiring higher levels of oxygen in the surrounding environment in order to burn. Wool may be ignited if subjected to a significantly powerful heat source, but does not normally support flame, and will instead smolder, usually only for a short time. In addition, wool’s cross-linked cell membrane structure will swell when heated to the point of combustion, forming an insulating layer that prevents the spread of flame. This also means that wool produces less smoke and toxic gas than synthetic fibers.
Wool based FR fabrics are used widely in personal protective equipment (PPE) to protect firemen, military personnel and anyone else exposed to fire or explosives. Wool’s characteristic of only smoldering and not melting or dripping onto skin, can itself be a lifesaver.