What is the typical ratio of water to foam concentrate used for Class B fires?

The typical ratio of water to foam concentrate for Class B fires is indeed 94-98% water to 2-6% foam concentrate. This concentration is crucial because Class B fires involve flammable liquids, and a higher proportion of water ensures that the foam can successfully blanket the fuel surface, preventing re-ignition and suppressing the fire effectively.

Water serves as a cooling agent, while the foam concentrate creates a film that helps to smother the fire by cutting off the oxygen supply. The standardized ratio allows for effective fire suppression while minimizing the volume of potentially hazardous chemicals introduced into the environment. This careful balance is what makes the fire fighting efforts more effective in controlling flammable liquid fires compared to other options with substantially different ratios.