Next time you go to a theatre or concert, just imagine what might happen if a fire broke out on stage. In fact in any public place such as a shop, school, library, restaurant, hotel, council building or anywhere people gather together. Even in your own home there are risks of a fire breaking out, but don’t be too alarmed, there are many ways of minimising the damage and preventing flames and smoke from spreading. The obvious ones come to mind, such as fire doors and extinguishers etc, but perhaps less evidently, you can ensure that the fabrics and materials used are fire-retardant too.
Fortunately, British Standards have been put into place to regulate how fabrics and textiles can be pre-treated to make them more resistant to fire depending on their intended use. Curtains, window blinds and drapes for example are covered by BS 5867, which indicates that they have been thoroughly tested using flames, cigarettes and other heat sources and must withstand these. To comply with this standard, curtains must carry a permanent label and must be cleaned professionally so that they do not lose their resistance to fire. Another standard, BS 5862 covers upholstery against burns by lit cigarettes, matches or a newspaper that has caught fire.
Some fabrics are treated during manufacturing to be inherently, durably or permanently fire-retardant. Inherently flame-resistant fabrics are fabrics manufactured with fibres whose innate properties make them flameproof without a chemical finish. The actual structure of the fibre itself is not flammable. For inherently flame-resistant fibres, the protection is built into the fibre itself and can never be worn away or washed out. The fabric’s effectiveness will not be reduced by repeated washing or wear and as such these fabrics ensure optimum protection throughout the life of the garment. When exposed to flame, inherently flame resistant fibres in clothing swell and become thicker, forming a protective barrier between the heat source and the skin. This protective barrier stays supple until it cools, giving the wearer vital extra seconds of protection to escape.
Originally, the only fabrics that were permanently incombustible contained asbestos and fibreglass woven into them, but over time manufacturers and chemists developed textiles from polymer extruded filament fibres (nylon and polyester), along with additives that chemically bind to the fibres to provide flame resistance with no reaction to water. This process essentially renders these fabrics flame resistant for a lifetime. Since these treated fabrics will remain fire resistant for a lifetime under normal circumstances, the industry labels them durably flame-retardant.
Other fabrics are surface treated with chemicals to make them fire-resistant. During a fire, chemically dependent fabrics rely on a chemical reaction to extinguish the flame. This reaction is triggered by the heat of the fire and the amount of time the fabric is exposed to the fire. Because the flame-retardant treatment is a chemical treatment which is washed out with time, the fabrics will only conform to heat and flame standards for a limited number of washes. They are usually certified for a year at a time before they need to be professionally coated again.
A group of Texas scientists have developed a new nontoxic fire-resistant fabric that could revolutionise clothing and fabric technology. The fabric is composed of renewable ingredients like clay and chitosan, a natural compound extracted from shrimp and lobster shells. When heat is applied to the material, a coating bubbles out, producing a protective layer of foam that prevents the fabric from igniting. Pity it isn’t edible, it sounds delicious!
A final word of caution however, fire-retardant does not imply that a fabric will never burst into flame. It reduces the fire hazard, but in reality anything will burn if sufficiently high temperatures are reached and there is enough oxygen present.