Standard Safety fuse burns at which rate?

• A. 10 seconds per foot
• B. 20 seconds per foot
• C. 60 seconds per foot
• D. 40 seconds per foot

Answer: (D)

The main idea here is the fuse burn rate, which is how long it takes for a given length of fuse to burn. For standard safety fuse, the burn rate is about 0.3 inches per second. That means a full foot (12 inches) takes roughly 12 / 0.3 = 40 seconds to burn. So 40 seconds per foot is the correct timing, which is why this option best matches the typical specification used in timing blasting sequences.

If the burn rate were faster, say around 0.6 inches per second, a foot would burn in about 20 seconds, which would not align with standard safety fuse timing. If it were slower, like 0.2 inches per second, a foot would take about 60 seconds. The 40-second-per-foot rate sits in the commonly used range for standard safety fuse and gives a predictable, workable delay in blasting procedures.