Safety testing of explosives

The safety testing of explosives involves the determination of various properties of the different energetic materials that are used in commercial, mining, and military applications. It is highly desirable to measure the conditions under which explosives can be set off for several reasons, including: safety in handling, safety in storage, and safety in use.

It would be very difficult to provide an absolute scale for sensitivity with respect to the different properties of explosives. Therefore, it is generally required that one or more compounds be considered a standard for comparison to those compounds being tested. For example, PETN is considered to be a primary explosive by some individuals, and a secondary explosive by others. As a general rule, PETN is considered to be either a relatively insensitive primary explosive, or one of the most sensitive secondary explosives. PETN may be detonated by striking with a hammer on a hard steel surface (a very dangerous thing to do), and is generally considered the least sensitive explosive with which this may be done. For these facts and other reasons, PETN is considered one standard by which other explosives are gauged.

Another explosive that is used as a calibration standard is TNT, which was afforded the arbitrary Figure of Insensitivity of 100. Other explosives could then be compared against this standard.

Because there are different ways to set off explosives, there are several different components to the safety testing of explosives:

Used together, these numbers may be used to determine the potential threats afforded by energetic materials when employed in the field. It cannot be stressed enough that these figures are relative; when we determine that impact sensitivity of an explosive is lower for that of a tested explosive than PETN, for example, the number produced in the impact test is dimensionless, but it means that it is expected that it would take a greater impact to detonate it than PETN. Therefore, an experienced ordnance technician who works with raw PETN will know that the new explosive is not as sensitive with regards to impact. However, it could be more sensitive to friction, spark, or thermal issues. These conditions must be taken into account before any compound is to be stored, handled, or used in the field.

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