Under what condition is properly maintained lightning protection not required for explosives facilities?

• A. When NEW exceeds 1000 pounds
• B. When NEW is less than 500 pounds
• C. Only for outdoor facilities
• D. During maintenance days

Answer: (B)

Net Explosive Weight (NEW) is the total amount of explosive material in the facility that determines what safety measures are required. When the amount is very small—specifically less than 500 pounds—the risk of a lightning-induced ignition is low enough that a separate lightning protection system isn’t required, as long as the existing protection is properly maintained.

“Properly maintained” means the lightning protection system is kept up to code: components are intact, inspected regularly, bonded and grounded correctly, and any damage is repaired promptly. With these conditions met, the small quantity of explosives doesn’t justify the added complexity or cost of special lightning protection.

The other scenarios don’t fit because having more than 500 pounds increases the risk and typically requires the protective measures; protection requirements aren’t limited to outdoor facilities or tied to maintenance days.