Part of Unit: Combustion and Fire Behavior
Lesson Plan Overview / Details
Understanding the classifications of fire is vital because each has different extinguishment methods that must be used. Not knowing these classifications can lead to dangerous consequences.
- 2 Hours
California Career and Technical Education Standards
- PS.C.C1.2 Develop and maintain a constant awareness of potential problems.
- PS.C.C1.3 Process information effectively to make prompt and effective decisions.
- PS.C.C1.6 Apply critical thinking skills to perform in emergency response situations.
- PS.C.C3.2 Employ personal safety procedures to meet prescribed regulations.
California Academic Content Standards (Reinforced)
- ELA.9-10.R.CAGT.2.5 Extend ideas presented in primary or secondary sources through original analysis...3
Objectives and Goals
Students will be able to define and describe each classification of fire after completing this section.
Activities in this Lesson
- Activity #1 - Hooks / Set
- Classifications - Lecture
Understanding the classifications of fire and how they relate to the fire tetrahedron is important to firefighters. Knowing this information will aid them when choosing the correct extinguishment methods when fighting fire.
The classifications are as follows:
- Class A Fires: Also known as "ordinary combustibles", this classification includes materials such as wood, paper, vegetation, plastic, rubber, and plastics.
- Class B Fires: This involves "flammable liquids" and includes gasoline, diesel fuel, oil, paint, lacquer, and alcohols to name a few.
- Class C Fires: This classification involves "energized electrical" fires. This might include such things as appliances, transformers, transmission lines, and electrical motors. It is important to note that once the electrical source is removed, these fires typically become class A fires because of the material burning.
- Class D Fires: "Combustible metals" such as aluminum, potassium, magnesium, and titanium to list a few. It is important to note that it is not just the metal burning but in many cases metal dust will also burn and sometimes cause adverse fire behavior.
- Class K Fires: These are fires normally found in kitchens and involve materials such as greases and oils.
While the basis of this discussion pertains to identifying the classifications of fire, it is important to spend a little time relating extinguishment methods utilizing the fire tetrahedron. Keep this information brief as it will be addressed more in depth during future lessons. There may be other methods of extinguishment but these are some of the common forms.
Methods of extinguishment:
- Class A: Temperature reduction, fuel removal
- Class B: Fuel Removal, oxygen exclusion
- Class C: De-energize, temperature reduction
- Class D: Fuel removal, oxygen exclusion
- Class K: interruption of the chemical chain reaction through Saponification.
- Hey look, it's on fire! - Demo / Modeling
Using live fire as a demonstration can sometimes be a little tricky. It is important that you have a safe environment to produce this type of demo. A large open parking lot is often a good place. Be sure to obtain permission from your supervisor before conducting the demonstration. Also have a designated safety officer in PPE armed with extinguishing agents.
Be sure to always burn in a contained space such as a pan or small enclosed metal box. As each material is burning, use the time to review basic fire behavior information. Ask the students to cite the burn process for each material, what is the best method of extinguishment, and what are the products of combustion? Also ask them how some of these fires might ignite? Piloted or non piloted ignition?
- Class A: burn paper.
- Class B: lighter fluid
- Class C: Use prop like a toaster with paper and run the eletrical cord away from the prop. Be sure to review what makes an "energized electrical" fire. Obviously DO NOT plug in the prop.
- Class D: This is a little more difficult. What is commonly done is just show them some examples of metal without actually igniting them.
- Class K: Utilize a frying pan and a stove prop if you have one. Use the same fuel as the class B fire. This will give them a good visual on what it may appear in an actual setting.
These demos will many times initiate very good questions from the class. Be prepared to answer as this is a unique opportuniity to show them how fire burns.
- Quiz - Assessment
Utilize a quiz to assess that the information has been transferred. Often times a combination test works well. Half of the test can be short answer asking the students to define each classification of fire and to include examples.
The second half of the test is identification. Utilize photos of different types of fire and ask the students to identify which classification each belongs. This is often a great assesment tool as it can be a challenge to apply this type of information.