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Quantitative Risk Analysis in the Commercial Explosives Industry
William B. Evans; A-P-T Research, Inc., Huntsville, AL, USA
Keywords: Explosives, event frequency, consequences, risk criteria, IMESAFR
Abstract
Risk management has been, is, and always will be a required key competence for explosives
companies. While the large/global commercial explosives companies have significant internal
capabilities for risk management, smaller local companies and even medium-sized companies
will generally have only limited capabilities. Since the larger companies recognize any accident
in the industry will affect all companies, they are prepared to share their internal expertise and
knowledge with the broader industry. This is generally done through industry associations, such
as SAFEX International (SAFEX) and the Institute of Makers of Explosives (IME).
Risk management requires minimizing event frequencies and/or consequences. Explosives
companies try to manage both, but the business adage is “what one can’t measure, one can’t
manage.” Explosives companies are generally good on the frequency side with a significant
amount of historical data and standard methodologies, e.g., fault trees, to determine valid event
frequencies and measure the effectiveness of various approaches to reduce them. Prior to the
advent of Institute of Makers of Explosives Safety Analysis for Risk (IMESAFR), explosives
companies had no effective way to measure the consequences or the effectiveness of various risk
reduction approaches. IMESAFR has allowed explosives companies to move from Semi-
Quantitative Risk Assessment (SQRA) to full Quantitative Risk Assessment (QRA).
1 Background to Risk Management in the Explosives Industry
When the author, Bill Evans, joined the world’s largest commercial explosives in the late 1970s,
the conversion to formalized risk and hazard review systems was just starting. The impetus was a
series of significant explosives accidents globally and a growing realization that the approach to
risk management needed to be more rigorous. Prior to this, risk management generally consisted
of semiformal reviews by senior personnel and subject matter experts. Reviews would cover
such things as Piping and Instrumentation Diagrams (P&IDs), Process Flow Diagrams (PFDs),
project plans, and possibly use methodologies such as fault tree analysis to make the analysis at
least semi-quantitative. This approach worked very well for many decades, mainly due to two
factors:
1. The products manufactured and processes used had been evolving very slowly
2. Employees tended to be employees for life so senior employees really did understand their
products and process at a fundamental level
However, starting in the late 1950s, the explosives technology started to evolve more rapidly and
whole new technologies, e.g., ammonium nitrate/fuel oil (ANFO) and water-gels, were
appearing. The other major change was in the mining industries, with a strong trend towards
using very large open pit mines requiring very large amounts of explosives to operate efficiently.
This trend towards large pits coupled with other trends in this new mining method, requirements
