To what temperature must fire extinguishers containing only plain water be protected?

• A. 0 °C
• B. -20 °C
• C. -40 °C
• D. -60 °C

Answer: (C)

Fire extinguishers that contain only plain water must be protected to a minimum temperature of -40 °C. Water, when exposed to temperatures below this point, can freeze, rendering the extinguisher ineffective for its intended purpose. If the water inside the extinguisher freezes, it could lead to a blockage of the discharge valve or other components, making it impossible to use in an emergency situation.

Maintaining the extinguisher at this temperature ensures that it remains functional and ready for use in the event of a fire. Understanding the temperature requirements for different types of fire extinguishers is crucial for ensuring safety and preparedness in various environments, particularly in colder climates where low temperatures are more prevalent.