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Basic Fires / Extinguishers. Your Safety Comes First. What Is Fire ?.
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Basic Fires / Extinguishers Your Safety Comes First
What Is Fire ? Typically, fire comes from a chemical reaction between oxygen in the atmosphere and some sort of fuel(wood or gasoline, for example). Of course, wood and gasoline don't spontaneously catch on fire just because they're surrounded by oxygen. For the combustion reaction to happen, you have to heat the fuel to its ignition temperature.
Three Key Elements FUEL - something to burn, such as wood, paper, grass, or clothing. AIR - actually oxygen is needed, but that's part of the air. HEAT - a catalyst to start the fuel and oxygen combustion.
Sequence Of Events Here's the sequence of events in a typical wood fire: Something heats the wood to a very high temperature. The heat can come from lots of different things -- a match, focused light, friction, lightning, something else that is already burning... When the wood reaches about 300 degrees Fahrenheit (150 degrees Celsius), the heat decomposes some of the cellulose material that makes up the wood
Some of the decomposed material is released as volatile gases. We know these gases as smoke. Smoke is compounds of hydrogen, carbon and oxygen. The rest of the material forms char, which is nearly pure carbon, and ash, which is all of the unburnable minerals in the wood.
Chemical Reaction Chemical Reaction, is the chemical changes that occur during combustion. As far as campfires and other wood-burning fires go, we have control over fuel, air, and heat, but not the chemical reaction - it just happens.
Classes Of fire Combustible and flammable fuels involved in fires have been broken down into five categories: Class A fires - are fires involving organic solids like paper, wood, Esc Class B fires - are fires involving flammable Liquids Class C fires - are fires involving electricity Class D fires - are fires involving Metals Class F fires - are fires involving Cooking oils.
P.A.S.S. Technique: Most fire extinguishers operate using the following P.A.S.S. technique: 1. PULL... Pull the pin. This will also break the tamper seal. 2. AIM... Aim low, pointing the extinguisher nozzle (or its horn or hose) at the base of the fire. 3. SQUEEZE... Squeeze the handle to release the extinguishing agent. 4. SWEEP... Sweep from side to side at the base of the fire until it appears to be out. Watch the area. If the fire re-ignites, repeat steps 2 - 4.
