Fire Resistant (FR) apparel is made from treated materials that do not burn when exposed to fire, intermittent flames, and electric arcs, due to its chemical structure. Fire-resistant fabrics are used in apparel applications for personal protective equipment. These apparel and clothing items are designed with self-extinguishing properties to protect the wearer from injuries caused by flames and thermal exposure.
A flash fire is spread rapidly through a diffuse fuel, such as dust, gas, or the vapours of an ignitable liquid, without the production of damaging pressure. Flash fires are typically three seconds or less but are fast-moving and intense. The severity is contingent on environmental factors such as the fuel available and the efficiency of combustion.
Both treated and inherently fire-resistant fabrics are flame resistant for the useful life of the garment. The difference between them relates to the process used in making the final product fire-resistant. Treated cotton fabrics are given a fire-retardant chemical application, which the originally non-Fat fabric is immersed in after it is woven together. Inherent fabrics contain fibres with an FR polymer base so that there is no need for topical treatment.