Fire prevention and control refers to the prevention, detection, and extinguishment of fires, as well as related operations such as fire research, public education about fire hazards, and the upkeep and enhancement of fire-fighting equipment.
A forest fire is an open, freely spreading combustion that destroys the forest’s natural fuels, such as duff, grass, weeds, brush, and so on.
Because most fire services were solely concerned with suppressing fires, little formal attention was paid to fire prevention until after World War I. Since then, most cities have established some form of fire-prevention unit, whose staff focuses on raising public awareness, incorporating fire-prevention measures into building design, machinery design, and industrial activity execution, reducing potential fire sources, and equipping structures with extinguishers and other fire-fighting equipment.
A successful fire-prevention program must emphasize the necessity of increasing public awareness of fire causes and developing good fire-fighting techniques. Most cities’ building rules incorporate fire safety measures to lessen the effects and likelihood of fire. Buildings are designed to separate and enclose areas to prevent a fire from spreading; to include fire-prevention devices, alarms, and exit signs; to isolate equipment and materials that could cause a fire or explode if exposed to fire; and to install fire-extinguishing equipment at regular intervals throughout a structure. Paints and chemicals used to cover and impregnate combustible materials like wood and textiles have also been produced as fire-retardant building materials.
Electrical fires were found to be the most common type of fire in the United States (23 percent of all fires), followed by tobacco smoking (18 percent), heat caused by friction in industrial machinery (10 percent), overheated materials (8 percent), hot surfaces in devices such as boilers, stoves, and furnaces (7 percent), and burner flames (7 percent) (5 percent).
An alarm system, which warns people to evacuate a building immediately, alerts the fire brigade, and determines the location of a fire within a structure, is the most fundamental device for reducing the hazardous effects of fire. Aside from human-activated fire alarms, there are other automatic systems that may detect the presence of fire. Heat-sensitive devices, which are activated when a specific temperature is reached; a rate-of-rise detector, which is triggered by either a rapid or gradual increase in temperature; and smoke detectors, which detect changes in the intensity of light, in the refraction of light, or in the ionization of air.
Many public buildings have automated sprinkler systems, which spray water on a fire-affected area when a fire is detected. In buildings protected by sprinkler systems that suffered fires, the system destroyed fires in 65 percent of cases and controlled fires until other fire-fighting measures could be used in 32 percent of cases, according to data gathered from around the world. Water damage is a big issue with sprinkler systems, although it has been discovered that in most circumstances, this risk is insignificant compared to the damage that a fire could inflict.
Firefighting equipment comes in a wide range of sophistication, from buckets and extinguishers to the sophisticated yet portable apparatus utilized by fire services. The fire engine, which is equipped with hoses, ladders, water tanks, and tools, is the most popular of these. To carry out rescue actions, ladder and rescue trucks work in tandem with vehicles equipped with platforms that can be hoisted by hydraulic lifts. Fireboats are used to put out fires on ships and at the water’s edge.
Other than water, fire-extinguishing substances are employed to put out several sorts of fires. To put out oil fires, foaming agents are used. The addition of a chemical that reduces surface tension makes “wet” water, which can be employed in a clinging foam to protect the exterior of a structure near a fire source. Ablative water is a dense, heat-absorbing blanket formed by combining water with chemicals. When water is unavailable and a fire must be extinguished by suffocation, carbon dioxide is used. Electrical fires and burning liquids are put out using dry chemicals, whereas burning metals like magnesium and phosphorus are put out with dry powder. At room temperature, halogenated hydrocarbons, also known as halons, exist as liquefied gas or vaporizing liquids and hinder the flame chain reaction. Inert gas is used to extinguish gas, dust, and vapour flames, whereas steam is utilized to control fire in tight spaces.
Fighting a fire is a race against the clock. The first concern is to save any residents who may be trapped within a burning building. The priority is then given to any location where the fire could spread to a nearby structure. The over-and-under system is a common firefighting strategy. Working from within the structure, if possible, the bulk of the firefighting is done from below, with additional attack from above to prevent the fire from spreading upward.
Water-tank trucks are frequently required in rural regions, making the time issue even more crucial. The same equipment that is used to fight building fires is frequently utilized to fight bush, grass, and forest fires. Occasionally, aircraft are used to drop fire-retardant slurries or water mixtures on these fires.
Firefighting in pressurized spaces, such as spaceships, has also become important. In these conditions, the rate of combustion is substantially faster than at normal atmospheric pressure. To reduce fire threats to a minimum, strict construction rules are observed, and highly pressurized sprinklers are fitted to act instantly upon any combustion.