Each fire extinguisher is marked with 1A, 2A, 21B and other fire performance levels.
What does 1A stand for?
It represents that 72 wood strips of 500mm length were used in the experiment, and 6 wood sticks in each layer were piled into 12 layers of wood stacks. Pre-burn with 1L pilot fuel under the stack for 3 minutes. Then let the wood stack burn until it loses more than 50% of its weight. The fire is the most prosperous. When it is the most difficult to extinguish, use a fire extinguisher to extinguish the fire, indicating that the fire extinguisher has 1A fire extinguishing performance.
The fire extinguishing capacity of 1A fire extinguisher is not low! But only professional inspectors can successfully use it to extinguish a 1A fire, and non-professionals can reach the level of 60 to 70%.
What does 2A stand for?
2A uses 112 635mm wooden strips to do the same test with 7 piles per layer and 16 layers.
The larger the value in front of A, it means that the more wooden strips to test, the longer the wooden strips.
So 21B uses 21 liters of liquid (two-thirds of fuel and one-third of water) for fire extinguishing tests.
A fire of this size can be extinguished, indicating that the fire extinguisher has a 21B fire extinguishing performance.
If a fire extinguisher can extinguish several types of fires, mark several extinguishing performance levels.
For example: a 2kg ABC dry powder fire extinguisher marked with 1A and 21B means it has 1A and 21B fire extinguishing levels.