Dry chemical extinguishers that weigh under 150 pounds require hydrostatic testing every 12 years. What is the weight threshold?

• A. Under 150 pounds
• B. Under 100 pounds
• C. Under 200 pounds
• D. Under 250 pounds

Answer: (A)

Hydrostatic testing verifies that the extinguisher cylinder can safely contain its internal pressure over time. For dry chemical portable extinguishers, the testing interval depends on the size of the cylinder, with a specific cut-off used by standards: extinguishers weighing under 150 pounds are required to be hydrostatically tested every 12 years. This split reflects safety considerations and practical maintenance planning: smaller cylinders meet the 12‑year cycle, while heavier cylinders fall under a different schedule outlined by the code. So the weight threshold is under 150 pounds.