What factor determines the size of a portable extinguisher?

• A. The amount of fuel that can be extinguished
• B. The color of the extinguisher
• C. The brand
• D. The height of the mounting wall

Answer: (A)

The size of a portable extinguisher is determined by its capacity—the amount of extinguishing agent it contains. More agent means a larger, heavier unit that can discharge longer and handle a bigger or longer-lasting fire. Color, brand, or mounting height don’t change how much agent is inside, so they don’t set the extinguisher’s size. The rating helps indicate what fires it’s suitable for, but it’s the amount of agent that sets the physical size.