Institute of Makers of Explosives Safety Analysis for Risk (IMESAFR) is a software tool used to assess risk from commercial explosive activities. This tool is a supplement to the longstanding American Table of Distances (ATD) and other Quantity-Distance (QD) systems.
What Does It Do?
This software uses a Quantitative Risk Assessment (QRA) approach to figure out a level of risk for an explosives activity. IMESAFR calculates the probability of fatality to an individual person per year, as well as the probability of fatality to a group of individuals per year. In these calculations, the tool considers the probability of an explosive event happening based on the activity, the consequence if that event occurs, and the exposure those individuals have to the explosives.
Why Do I Need It?
Historically, the commercial explosives industry has relied on QD criteria. However, IMESAFR can provide a more comprehensive assessment of the risk, catered to an individual set of conditions. During its development, IMESAFR incorporated accident information on a variety of activity types conducted in the commercial explosives industry – activities beyond what is covered by QD.
IMESAFR considers explosives weights and types, distances to exposed sites, and barricading; but it also uses more information such as magazine and building construction, magazine orientation, and numbers of people in exposed sites. Using the QD method only yields a pass or fail answer. This black and white method doesn’t provide information about what is driving the risk. Quantifying the risk and showing where the hazard lies, rather than determining an acceptable distance, allows for better risk mitigation. Not all explosives scenarios have the same risk, but QD treats them the same if exposures are inside or outside the line. The figure below shows that QRA acknowledges the differences beyond quantity and distance while QD treats them the same.
Why Can I Trust It?
IMESAFR is an offspring of a Department of Defense (DoD) software, called SAFER, used for the same purpose except for DoD explosive activities. The Institute of Makers of Explosives worked with A-P-T Research, Inc., in collaboration with industry, regulators, and subject matter experts, to modify SAFER to fit the commercial sector.
This strong backing has led to IMESAFR use in 34 countries by industry and government. For example, the United States Bureau of Alcohol, Tobacco, Firearms, and Explosives (ATF) recognizes IMESAFR as a valid method for evaluating risk to the public within inhabited buildings and in vehicles on highways.
Unlike many theoretical-based blast effect models, IMESAFR uses physics-based algorithms, rooted by full-scale, real-world tests, to determine overpressure and debris scatter predictions. Tests performed, like the one on the left below, feed the models that are used in IMESAFR today. On the right is an example of IMESAFR’s visual representation of a debris density scatter contour.
How Do I Get It?
To purchase the software or sign-up for training, please visit IMESAFR » A-P-T Research, Inc. or contact imesafrtraining@apt-research.com.








Explosives site planning is a process used to manage the potential risks associated with Ammunition & Explosives (AE) to preserve mission or operational capability. When applied correctly, it aims to identify the acceptable level of risk to surrounding exposures. It is important to understand that site planning does not constitute risk-free protection from AE sources.
Some variables that impact PESs include Net Explosive Weight (NEW), Hazard Division (HD), type of explosives operation required, and type of structure. ESs are also impacted by various factors such as occupancy, type of structure, criticality of the exposure, relationship to the PES, and even NEW. Remarkably, PESs are often ESs themselves and require a specific set of criteria inside the assessment.
The most important factor to consider is that explosives site planning does not mean you are operating in a risk-free environment. The criteria that are approved for accidental detonations are based on the acceptable level of risk for the applicable explosives storage and operations. Consideration must be given to vulnerable facilities that are outside but near explosives clear zones as well. Vulnerable facilities include schools, hospitals, daycare centers, and family housing areas. The Department of Defense Explosives Safety Board (DDESB) recommends site plans be submitted for these areas prior to construction. This same practice is recommended for similar facilities that reside outside an installation or site boundary since absolute safety is not provided just because a facility is located beyond an explosives clear zone.