Which classes of fire extinguishers include numbers in their classification?

Which classes of fire extinguishers include numbers in their classification?

• A. A & B
• B. A, B, C
• C. A only
• D. B only

Answer: (A)

Numbers in extinguisher classifications show how much extinguishing power is available for specific fire types. For fires involving ordinary combustibles like wood and paper, the rating uses a number with the A class (for example, 2-A), indicating water-equivalent capacity. For fires involving flammable liquids, the rating also uses a number with the B class (such as 10-B), reflecting the approximate area the extinguisher can cover. Fires involving electricity are labeled with the C designation without a numeric value, because the key concern is electrical safety rather than a fixed extinguishing capacity. So, the classes that include numbers are those for ordinary combustibles and for flammable liquids, which is why the option listing both is the correct choice. For example, a common multi-class rating might look like 2-A:10-B:C, combining both A and B numeric components with C.

Numbers in extinguisher classifications show how much extinguishing power is available for specific fire types. For fires involving ordinary combustibles like wood and paper, the rating uses a number with the A class (for example, 2-A), indicating water-equivalent capacity. For fires involving flammable liquids, the rating also uses a number with the B class (such as 10-B), reflecting the approximate area the extinguisher can cover. Fires involving electricity are labeled with the C designation without a numeric value, because the key concern is electrical safety rather than a fixed extinguishing capacity. So, the classes that include numbers are those for ordinary combustibles and for flammable liquids, which is why the option listing both is the correct choice. For example, a common multi-class rating might look like 2-A:10-B:C, combining both A and B numeric components with C.