What rating must at least one portable fire extinguisher have when located outside a room storing more than 60 gallons of flammable liquids?

A portable fire extinguisher located outside a room that stores more than 60 gallons of flammable liquids must have a rating of at least 20B. This rating is in accordance with fire safety regulations, particularly the National Fire Protection Association (NFPA) guidelines and the Occupational Safety and Health Administration (OSHA) standards.

The "B" in the rating system indicates the extinguisher's effectiveness against flammable liquid fires, with the number representing the square footage of fire coverage the extinguisher can effectively protect. A rating of 20B signifies that the extinguisher is capable of extinguishing a fire in a flammable liquid area that covers 20 square feet. This level of readiness is essential in environments where large quantities of flammable liquids are stored, as it ensures that sufficient firefighting resources are available to manage potential fire hazards effectively.

Therefore, having a 20B rated extinguisher is crucial in minimizing risks and ensuring safety in such critical storage situations.