Class A portable fire extinguishers are rated based on the amount of water and which additional factor?

Class A portable fire extinguishers are rated based on how effective they are at extinguishing fires involving ordinary combustibles, such as wood, paper, and cloth. The rating reflects two main factors: the amount of water that the extinguisher can deliver and its effectiveness in terms of the duration and range of the discharge.

The duration relates to how long the extinguisher can continuously discharge its contents, which is crucial in a firefighting scenario. A longer discharge time allows the firefighter to apply the extinguisher effectively without requiring constant reapplication. The range indicates how far the extinguisher can project its discharge, allowing for safer operation when attacking a fire from a distance, thus reducing the risk of injury from heat or flames.

In summary, the rating of Class A extinguishers considers both the volume of the extinguishing agent and the performance characteristics (duration and range) that determine how effectively a firefighter can combat a fire.