Underwriters Laboratories fire extinguishers tell you

• A. The weight of the extinguisher
• B. The extinguishing capabilities of the extinguisher
• C. The color code
• D. The operating temperature

Answer: (B)

The main point is that the labeling from a fire extinguisher’s Underwriters Laboratories listing communicates its extinguishing capabilities. The rating shows how effective the extinguisher is on different fire types (class A for ordinary combustibles, B for flammable liquids, C for electrical fires) and uses numerical values to indicate performance in standard tests. This is what you use to judge whether an extinguisher is appropriate for the hazards present.

Weight, color code, and operating temperature are separate specifications and not what the UL rating conveys. So you look at the UL-rated extinguishing capabilities to determine suitability for the fire hazards you’re preparing for.