Explosives Safety & Handling Flashcards
7 cards from real CES 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 Safety & Handling flashcards as text
Under 27 CFR Part 555, who is legally responsible for maintaining an accurate inventory record of all explosive materials at a licensed facility?
Answer: The licensee or permittee
The ATF licensee or permittee bears legal responsibility for maintaining accurate acquisition and disposition records of all explosive materials at their facility.
What environmental condition MOST significantly reduces the reliability of a non-electric (Nonel/shock tube) initiation system?
Answer: Severe kinking or crimping of the shock tube
Kinking or crushing the shock tube disrupts the thin reactive dust coating inside, blocking signal propagation and causing a misfire.
Which type of magazine construction is required for permanent storage of high explosives under ATF Type 1 specifications?
Answer: Bullet-resistant, theft-resistant wood or metal construction with specific wall thickness requirements
ATF Type 1 magazines must meet specific bullet-resistance, construction, and security standards including double-wall construction with barriers and robust locking mechanisms.
When performing a resistance check on an electric blasting circuit, what instrument must be used?
Answer: A blasting galvanometer or approved low-current ohmmeter
Only an approved blasting galvanometer or low-current ohmmeter designed for the purpose may be used; standard meters can deliver enough current to accidentally fire a cap.
What does 'back break' refer to in the context of blasting operations?
Answer: Fracturing of rock beyond the intended blast boundary
Back break is unplanned fracturing of rock or material behind or beyond the last row of holes, often caused by excessive powder factor or insufficient burden.
Which factor determines the 'burden' in a surface blast design?
Answer: The distance from the front row of holes to the free face
Burden is the perpendicular distance from a blasthole to the nearest free face, and it is the primary variable controlling fragmentation size and blast efficiency.
Under OSHA 29 CFR 1926.900, which personnel are explicitly prohibited from handling or using explosive materials at a construction site?
Answer: Persons under the influence of alcohol or narcotics
OSHA explicitly prohibits any person who is under the influence of alcohol, narcotics, or other intoxicants from handling, using, or being in proximity to explosive materials.