To what temperature should a hole be cooled before packing explosives?

To what temperature should a hole be cooled before packing explosives?

• A. 140 F
• B. 150 F
• C. 160 F
• D. 130 F

Answer: (B)

Heat remaining in a borehole after drilling can transfer to the explosive during loading. If you pack into a hot hole, the heat can accelerate decomposition or initiate the charge unintentionally, leading to a dangerous cook-off or misfire. Cooling the hole to a safe temperature—about 150 degrees Fahrenheit—helps keep the explosive stable and predictable, preserving both safety and the planned timing of the blast. Practically, 150°F is a chosen limit that balances reducing heat risk with not causing excessive delays in operations.

Heat remaining in a borehole after drilling can transfer to the explosive during loading. If you pack into a hot hole, the heat can accelerate decomposition or initiate the charge unintentionally, leading to a dangerous cook-off or misfire. Cooling the hole to a safe temperature—about 150 degrees Fahrenheit—helps keep the explosive stable and predictable, preserving both safety and the planned timing of the blast. Practically, 150°F is a chosen limit that balances reducing heat risk with not causing excessive delays in operations.