MSHA Explosives and Blasting 2

Question 1

What is 'flyrock' in the context of surface mine blasting, and what is the primary MSHA concern?

Accepted Answer

Rock propelled beyond the intended blast area, posing a hazard to workers and the public

Answer

A type of explosive used in quarries

Answer

A blasting technique used to break large boulders

Answer

The fine dust generated after a blast detonates

Question 2

According to MSHA regulations, the magazine used to store explosives at a mine must be:

Accepted Answer

Located a safe distance from roads, occupied buildings, and other magazines per MSHA tables

Answer

Located within 100 feet of the active mining area for quick access

Answer

Constructed of metal to prevent theft

Answer

Above ground only, even at underground mines

Question 3

What is a 'bootleg' in blasting terminology, and why is it dangerous?

Accepted Answer

An unbroken portion of a borehole remaining after a blast that may contain undetonated explosives

Answer

An illegally obtained explosive

Answer

A type of fuse used in underground blasting

Answer

Explosive material left out of an approved magazine overnight

Question 4

Under MSHA standards, electric blasting circuits must be tested before firing using:

Accepted Answer

A blasting galvanometer or approved circuit tester designed for explosives use

Answer

A standard multimeter set to the highest voltage range

Answer

A 9-volt battery to check continuity

Answer

Any available electrical testing device on site

Question 5

What is 'sympathetic detonation' in the context of explosives storage?

Accepted Answer

The accidental detonation of an explosive charge caused by the shock wave of a nearby explosion

Answer

A blasting technique that uses multiple delay detonators

Answer

A method of disposing of old or deteriorated explosives

Answer

When a blaster voluntarily detonates a charge to relieve pressure

Question 6

According to MSHA, what action must be taken with deteriorated or damaged explosives?

Accepted Answer

They must be disposed of according to manufacturer instructions and applicable regulations

Answer

They may be used if the damage is minor

Answer

They should be returned to the main magazine for later inspection

Answer

They can be combined with fresh explosives to boost effectiveness

Question 7

What is 'stemming' in a blasting operation, and what material does MSHA recommend?

Accepted Answer

An inert material placed on top of the explosive in a borehole to confine the blast energy

Answer

A method of connecting detonator wires

Answer

The process of drilling the borehole before loading

Answer

A type of delay element used in millisecond detonators