Understanding the nature of energetic material is crucial when storing, handling, processing, or transporting these types of materials. We can only fully understand the nature of explosives through appropriate testing. There are specific tests required to be performed on a substance or article in order to understand and classify an explosive. The idea of these tests is to put the substance or the article through a set of challenging environments in order to determine the sensitivity to certain stimuli.
These series of tests can generally be placed into two subcategories of sensitivity and reactivity testing. Sensitivity testing can be used to understand the nature of an explosive under normal transportation and working environments. Some of these sensitivity tests include electrostatic discharge testing (ESD), friction, impact and thermal stability testing. These tests help asses if the nature of the substance itself is hazardous to normal transportation and shipping regulations. Generally, if a test fails a thermal stability test then transportation is forbidden.
The second set of tests are reactivity testing. These tests can include tests like critical height testing, TNT equivalency testing, propagation testing or #8 cap test. These tests see how an explosive will react when surrounded or packaged with similar explosives. Depending on how these explosives react with one another is how entities like DoT classify the explosives. In addition, in-process classification and testing is integral to the safe design of an operation. These tests allow companies to identify and test within to determine hazardous situations.
Once completed, the data from these tests is to be analyzed and processed. Some ways in which Safety Management Services analyses include Threshold Initiation Level (TIL) and PROBIT analysis. The TIL is defined as the level above where there are no reactions after 20 trails. That is why it is considered a threshold level, because it is at the threshold of where reactivity occurs. The PROBIT method of analysis is a statistical evaluation of the testing data using the TIL, as well as the next four higher levels of testing performed. This uses 10 trials and provides some prediction of how a substance may react at a certain stimulus level. It is a powerful tool that can be used when performing quantitative analysis to determine the probability of an incident.