# Fire and Emergency Management/Fire Fighter I
## The Chemistry of Fire

Fire is a chemical reaction. Specifically, fire is an oxidation process that releases energy in varying intensities in the form of light (with wavelengths also outside the visual spectrum) and heat and often creates smoke. It is commonly used to describe either a fuel in a state of combustion (e.g., a campfire, or a lit fireplace or stove) or a violent, destructive and uncontrolled burning (e.g., in buildings or a wildfire).
.. a more thorough discussion of the chemistry of oxidation is needed.

## The Physics of Fire Control

... a discussion of the four elements of fire control is needed
Fuel .. a discussion of fuels and their flash-points are needed for a firefighter to understand the dangers of fighting various materials and the importance of recognizing what is needed to protect uncombusted elements that may be adjacent to an incident.
Heat .. a discussion of the laws of thermodynamics would be helpful in aiding a firefighter's understanding regarding how best to control a fire from this perspective.
Oxidizer .. a discussion of the sources of oxygen during a fire event is needed to aid the firefighter's ability to avoid making structural errors in increasing the progression of a fire.
Self-Sustaining Chemical Reaction ..a discussion of how a fire event is a chemical reaction and must be self-sustaining

## Fire types, or Classes

It is critical to understand the class of fire so as to select the proper method of fighting it. Most fires begin as one class but may involve other classes as the fire progresses. Recognizing the signs of the different classes may be tricky, and are usually assumed based on the context of the location of the fire.
Class A
    Letter Symbol is a capital 'A' inside a triangle.
    Graphic Symbol: a trash can with fire emanating from the top beside a crude campfire, all inside a green square.
       Class A fires involve the combustion of mostly organic solids such as coal, wood, paper, cloth, rubber, and many plastics where the combustion elements do not change form when heated (eg. solid asphalt or wax, when heated becomes liquid, the resultant fire fighting tactics may need change to class 'B').
Class B
    Letter Symbol: a capital 'B' inside a solid red square.
    Graphic Symbol: a portable liquid fuel container "Jerry Can[[[w:Jerry_can]]]" with a spout, tilted to the right with liquid on the ground which is ablaze. The symbol is contained inside a red square
    Class B fires involve the combustion of flamable liquids or gases such as Natural gas, propane, butane, greases, oils (petroleum, vegetable, etc), Most petroleum products: tar, gasoline, Kereosene, turpentine, and paint thinners.
       Class K
          Recently recognized by NFPA 10: a subclass to Class 'B' limited to combustible vegetable or animal cooking fats in commercial cooking equipment.
Class C
    Letter Symbol: a capital letter 'C' inside a solid blue circle.
    Graphic Symbol: a side view of a two prong (120 volt) male plug on a wire over the end view of a female (120 volt) plug which is involved in flame. The symbol is in a Blue square box.
       Class C Fires are those which involve energized electrical equipment. Fires may be caused by short circuiting, or an overdraw of current through inadequate wiring, or an improperly grounded circuit. Class C fires do not always start as a result of an electrical malfunction but almost always involve other fire classes. An electrocution hazard must always be assumed when a fire is designated class 'C')
Class D
    Letter Symbol: a capital letter 'D' inside a solid yellow five point star.
    Graphic Symbol: there is no graphic symbol for Class 'D' fires.
       Class D fires involve burning metals: magnesium, titanium, sodium, lithium, potassium and zirconium.