BASIC CHEMISTRY OF EXPLOSIVES AND HAZARDS OF HOME-MADE EXPLOSIVES AND CHEMICAL PRECURSORS

The widespread use of improvised explosive devices (IEDs) has been documented extensively by the mine action sector over the last decade1. Together with this trend is the use of home-made explosives (HMEs). Although not all IEDs include an HME component, the frequency of their use and the specific operational challenges related to HMEs and their chemical precursors, have highlighted the need to document good practice related to this lesser-known category of explosives.

The importance of addressing HMEs is clear. They pose a threat to human life and to the environment. There is also a significant risk that mine action (MA) personnel will encounter HMEs in affected countries, whether in improvised explosive devices (IEDs), in abandoned manufacturing or storage sites, or as stockpiles of precursor chemicals used in a variety of industries. The severity of the impact of HMEs coupled with a high likelihood of encountering them in certain settings, led to the decision to develop guidance that is focused on HMEs.

Given the risks involved for those in encountering HMEs and potentially interacting with them, the GICHD has developed Chapter 5 of the Improvised Explosive Device Clearance Good Practice Guide with the aim of improving the safety of mine action personnel as a first priority, but also ensuring that mine action programmes are dealing with this particular threat effectively to keep communities safe from their effects. This guidance therefore provides an important component of the mine action knowledge necessary to conduct IED search and disposal activities within the IED clearance process in relevant settings.

Our aims for this chapter have been addressed by presenting technical information on HMEs that will promote an increased understanding of these substances, including: the raw materials that compose HMEs; the ability to recognise their presence; the physical and chemical characteristics of HMEs; their potential to generate non-explosive hazards, such as toxicity; and, safety considerations for mine action personnel who are likely to encounter HMEs (such as Personal Protection Equipment (PPE)).

In order to strengthen and reinforce the knowledge about HMEs and their chemical precursors in the MA sector, this publication presents a wide variety of HMEs that can be encountered in operational contexts, and the chemical compositions used in their explosive train. Apart from discussing the more common HME groups (chlorates, perchlorates, nitrates and peroxides), substantial information has been provided on less commonly found mixtures, as well as on improvised pyrotechnics, improvised incendiary compositions and improvised primary explosives.

This chapter is neither a research publication nor a comprehensive technical manual; it rather aims to provide condensed content in an easy-to-read format. Visual aids and images of these chemical compositions are provided throughout the chapter to reinforce the learning process. The content has been chosen to provide practical knowledge to mine action practitioners, based on the most common HME threats they will encounter. Theoretical knowledge of the very basic chemistry of explosives and their chemical precursors provides the foundation of this document. Detailed scientific information, such as complex equations and formula have been avoided. Definitions and derivations have also been simplified to provide only the most essential information for end-users.

It is hoped that the technical knowledge presented in this chapter will be a useful operational resource that enables MA personnel to meet their primary needs for identifying and assessing chemical behaviour, as well as the risks related to non-explosive hazards. At the same time, reliable and accessible technical information also provides the foundations for high quality national standards, operational procedures, and policy documentation. We therefore hope that this chapter also proves useful in terms of developing the frameworks for MA programmes where IEDs are present.