Back to Firefighting Basics

10 Firefighting Phrases You Need to Know

(Fire Science Colleges)

Like any industry, firefighters also have their own phrases, terms and lingo to communicate with each other while on the job. Using short phrases and specific terminology allows firefighters to reach their destination prepared and ready to tackle the flames in a quick and efficient manner. Here are 10 firefighting phrases and terms you need to know:

1. Two-In, Two-Out
   The phrase, “two-in, two-out” refers to firefighting in teams of two, so that firefighters are never left alone during dangerous tasks. There must be at least two firefighters together when entering and exiting a structure. While inside, they must have direct visual or voice contact with one another, as well as voice or radio contact with the firefighters outside.
2. Sides A, B, C, D
   Sides A, B, C and D are labels that help firefighters distinguish each side of a building. From the outside of a building and going in a clockwise direction, side A or Alpha is the front of the structure. The left side is B or Bravo, the rear side is C or Charlie and the right side is D or Delta.
3. Size-Up
   A size-up is a term for the initial evaluation of an incident. Firefighters size-up an incident by reporting the extent of the fire and potential hazards they may face, such as occupancy, location and path of fire, type of smoke, resources needed and additional information that will make the search and rescue process more efficient.
4. Fully Involved
   Fully involved is a size-up term that means fire, heat and smoke are blowing out of every entrance in a structure. When a fire is fully involved, firefighters must apply fire streams before they can enter the burning building.
5. Flashover
   A flashover is the simultaneous ignition of combustible materials in an enclosed space, and is the most dangerous stage of a fire. A flashover occurs when certain materials become heated and release flammable gases that reach an auto-ignition temperature, causing the materials to combust and the room to burst into flames. The average temperature of a room that flashes over is anywhere from 1,000 to 1,500 degrees Fahrenheit.
6. Strike The Box
   The phrase, “strike the box,” was used in early firefighting, when firefighters would strike a bell or box on the wall to signal an emergency call. Some of today’s stations still say, “strike the box,” to alert their dispatch center to send more fire engines.
7. First Due
   The phrase, “first due,” signifies the first fire engine at the scene of the emergency. This engine group will typically size-up the fire, prepare for extinguishing and call for back up if they need the second due fire engine.
8. Code-1
   Code-1 is a low priority emergency call for fire fighters to respond as soon as possible, without lights and sirens.
9. Code-2
   Code-2 is a medium priority emergency call that means to respond now, using lights and sirens if necessary.
10. Code-3
    Code-3 is a top priority emergency call that tells firefighters to respond right away, using their lights and sirens and expediting.