Combustion firefighting

Mobile sources include railroad locomotives, marine vessels, aircraft, and automotive vehicles. Over the past 100 years, we have gained much experience in regulating smoke and odor emission from locomotives and marine craft. Methods of combustion equipment improvement, firefighter training, and smoke inspection for these purposes are well documented. This type of control is best at the local level. 

One of the most hazardous conditions a firefighter will ever encounter is a backdralt (also known as a smoke explosion). A backdraft can occur in the hot-smoldering phase of a fire when burning is incomplete and there is not enough oxygen to sustain the fire. Unburned carbon particles and other flammable products, combined with the intense heat, may cause instantaneous combustion if more oxygen reaches the fire. 

Properly applied firefighting foam can be an effective fire suppressant for most flammable or combustible liquids stored in vertical cylindrical tanks. Foam may... 

For those process vessels containing a significant quantity of flammables or heated combustibles, a combination of passive and active fire protection should be considered in addition to manual firefighting. This additional protection is usually in the form of fireproofing and fixed sprinkler or directional water spray. Additional vessel protection should be applied as follows ... 

Cable tray fires have resulted from the accumulation of process leakage, residues or combustible dusts or debris on top of cable trays with densely packed wires and cables. Covering shields above cable trays have been used to minimize such accumulations however, such shields should be used with caution as they can limit air circulation and increase cable and wire temperatures in densely loaded trays particularly those carrying power cables. Covering shields may also block fixed fire protection water spray or manually applied firefighting water spray from reaching the cables. 

Firefighting foam is the extinguishing agent typically utilized for flammable and combustible liquid storage tank protection. Protection is through fixed and manual systems for tanks. Such systems require ... 

If the outdoor stored material consists of flammables or combustibles in containers or combustible bulk piles, an adequate number of hydrants should surround the area with approximately 200 ft (61 m) between each other and the material to be protected to allow manual firefighting. 

Fires are classified based on the type of fuel involved. Fuels are typically placed into three classes ordinary combustibles (like wood and paper), flammable liquids, and combustible metals. For firefighting, a fourth fire class, electrical fires, is also considered. The four main classifications of fire are shown in Table B-1. 

Independent of combustibility or reactivity, chemicals may exhibit hazardous properties that affect fire protection, in particular firefighting. Chemicals may be inherently toxic or radioactive. In either situation, potential exposure of smoke/gases to personnel from the burning of materials exhibiting these characteristics needs to be addressed. 

Polymers form the basis for fire-resistant textiles. For instance, many of the firefighters and race car drivers wear clothing made from aromatic nylons because these materials resist melting, dripping, supporting combustion in air, or burning. 

Rain drops Combustion engines Soap bubbles Foam (in firefighting)... 

To reduce those risks, it is critical that firefighters stay in top physical condition and master the use of various equipment and tools. But it is equally critical that they have a knowledge bank filled with scientific and technical information about combustible materials, building construction, ventilation systems, sprinkler systems, electrical circuitry, chemical reactions, and a host of other subjects. Firefighters are educated, trained, and drilled again and again in each of these critical areas. 

Academy training generally lasts several weeks, with part of the time spent on classroom instruction and part on practical training. You will cover areas such as firefighting and prevention techniques, hazardous and combustible materials, local building codes, and emergency medical procedures. You will also learn how to use various kinds of firefighting and rescue equipment. 

Firefighters have to be able to read, understand, and act on complex written materials—not only fire law and fire procedures, but also scientific materials about fire, combustible materials, and chemicals. They have to be able to think clearly and independently because lives depend on decisions they make in a split second. They have to be able to do enough math to read and understand pressure gauges, or estimate the height of a building and the amount of hose needed to reach the third floor. They have to be able to read maps and floor plans so they can get to the emergency site quickly or find their way to an exit even in a smoke-filled building. 

Reports (Boettner et al., 1973 DuPont, 1981) on the combustion products of polyurethanes show that the levels of carbon monoxide in an oxygen-deficient burning condition can reach 290 to 640 mg per gram of sample burned, with cyanide (as HCN) up to 34 mg per gram of sample burned. This data is from laboratory tests and may not represent actual combustion conditions. Professional firefighters should be involved in all situations in which there is an uncontrolled fire in a polyurethane plant. 

Smoke can obscure vision and exits, thereby retarding escape and resulting in panic. It also hinders the work of firefighters. The particular fraction of smoke, exclusive of any combustion gases, acts as an irritant to the respiratory system and may also result in hypoxia and collapse (39). 

Fire-fighting measures Suitable (and unsuitable) extinguishing media. Specific hazards arising from the chemical (e.g. nature of any hazardous combustion products). Special protective equipment and precautions for firefighters. 

Observe normal precautions appropriate to the circumstances and quantity of material handled. Chitosan is combustible open flames should be avoided. Chitosan is temperature-sensitive and should not be heated above 200°C. Airborne chitosan dust may explode in the presence of a source of ignition, depending on its moisture content and particle size. Water, dry chemicals, carbon dioxide, sand, or foam firefighting media should be used. 

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