EXUDATION AND CRYSTAL GROWTH OF TNT IN MUNITIONS

Abstract

For trinitrotoluene (TNT), exudation has been a recurring problem since the early 1920s. TNT exudate typically has an oily appearance and dries to a somewhat black color. Exudate, by itself, appears to be no more sensitive than TNT. However, if mixed with sand or grit, it can be very sensitive to impact or friction. Munitions which exhibit TNT exudate except where the design allows, should not be considered as safe and suitable for service. TNT exudate is formed due to the presence of impurities and the high temperatures that can be experienced in the service environment. Older TNT manufacturing methods leave significant impurities within the TNT, whereas more modern methods have improved the quality of the processed TNT, removing most but not all impurities. Another potential issue with exudation is crystal growth. There is some discussion within the munitions safety community that TNT crystals can grow within cavities of aged munitions. However, we believe that internal fill exudate and TNT crystal growth does not constitute a major concern for munition safety if standard munition handling practices are observed.