Explosives and Blasting Flashcards
7 cards from real MSHA practice questions. Tap to flip, then mark Knew It or Still Learning — missed cards come back until you master them.
Read the first 7 Explosives and Blasting flashcards as text
Under MSHA regulations, who is authorized to handle and use explosives in underground mines?
Answer: A certified blaster who holds a valid blaster's certificate
MSHA 30 CFR Part 57 requires that only certified blasters who hold a valid blaster's certificate are authorized to handle and use explosives in underground metal and nonmetal mines.
What is the minimum distance that must be maintained between detonators (blasting caps) and other explosives during transportation in a mine?
Answer: Detonators must be transported separately from other explosives
MSHA regulations require that electric detonators and other explosives be transported separately to prevent accidental initiation.
Before loading explosives into a borehole, MSHA requires that the hole be checked with which of the following?
Answer: A wooden or non-sparking loading stick
MSHA requires the use of a non-conductive, non-sparking wooden or plastic loading stick to prevent accidental detonation when loading explosives.
According to MSHA standards, what must be done if a misfire (failed blast) is suspected in an underground coal mine?
Answer: Wait at least 30 minutes before returning and follow specific misfire procedures
MSHA regulations require miners to wait at least 30 minutes before re-entering an area with a suspected misfire and to follow strict procedures to safely handle the unexploded charge.
What type of container is required by MSHA for storing electric detonators (blasting caps) at a mine site?
Answer: A separate locked magazine, apart from other explosives
MSHA regulations require that electric detonators be stored in a separate locked magazine away from other explosives to reduce the risk of sympathetic detonation.
Under MSHA rules for underground coal mines (30 CFR Part 75), permissible explosives are required because they:
Answer: Produce a flame and gas that will not ignite coal dust or methane
Permissible explosives are specially formulated so that their detonation flame and gases will not ignite coal dust or methane gas, which is critical for safety in gassy coal mines.
What does MSHA require regarding the posting of warning signs during blasting operations?
Answer: Warning signs must be posted at all entrances to the blast area before detonation
MSHA requires that warning signs be posted at all entrances to the blast area to prevent unauthorized personnel from entering during blasting operations.