Fire Retardants
A fire retardant is basically a substance that helps to delay or prevent combustion. They are commonly used in fire fighting by a team of fire fighters. It is used as fire safety equipment. Fire retardant can be worth hundreds of times its cost in minimizing premise damage in the event of fire. This type of fire safety equipments can be used for interior as well as for exterior woods and foe all other types of materials and fabrics that are used in offices and buildings. Water is the most commonly used fire retardant but the term fire retardants typically lead to chemical retardants and sprays. Because of the importance of prevention they have become a very important industry. These retardants are available in the form of adhesives, coatings and as thermal paste.
They are safe as when fire retardants are sprayed on the burning objects; a chemical reaction is initiated that stops the fire. It also reduces the flammability of materials by blocking the fire physically. As fire retardants work either physically or chemically, these two processes are again further divided into couple of processes. There are several processes by which the process of burning can be retarded by physical means and they are:
- By cooling
- By forming a protective layer
- By dilution
As cooling is considered as the most effective method in which combustion can be stopped or retarded as there are some chemical reactions that actually cools down the burning material. Another method is by forming a protective layer as it is not that effective as with the help of this method one can only protect the remaining materials. The dilution method is such that as some retardants release water and carbon dioxide while burning and this may dilute the radicals in the flame. A commonly used fire retardant is aluminum hydroxide. The best part about this chemical is that it breaks down to give off water vapor. It also absorbs a vast amount of heat and the residue of aluminum hydroxide that is left behind forms a protective layer. Alum has also been mentioned as a fire retardant for wood.
Next is the chemical ways by which these fire retardants work. The chemical reactions in the flame can be interrupted by fire retardants and generally this class of fire retardants uses halogens such as bromine, or chlorine. Whenever there is a reaction in solid phase in that case they work by breaking down the plastics polymer as it melts and flows away from the flame. There are also solid phase fire retardants and they are those which cause a layer of carbon char to form on the polymer surface which in turn does not burn easily. It is also possible to coat certain materials with the help of these kinds of fire safety equipments. One great way in which a chemical fire retardant can be used is at a wildfire and can be used to protect and save it.