The most modern formulation of an RDX-based plastic explosive used in the US Military is Composition C4, commonly called just C4. C4 is a stable, powerful, flexible explosive that will not detonate from impacts as strong as a rifle bullet. Standard primercord and military-grade detonators will initiate C4 with regularity when properly applied. The flexible, plastic nature of C4 allows it to be formed against a target to maintain maximum contact area, useful when cutting steel or shattering concrete. Plastic explosive, of which C4 is one formulation, has become the standard military explosive in most of the world’s militaries. Many countries have developed their own formulations to meet their specific resources and demands. More powerful than TNT, C4 has replaced that material as the standard explosive that US Military demolition calculations are based on. It can be used at higher, and lower, temperatures than earlier Composition C formulations. It does not lose its plasticizer at warm temperatures, or easily freezes. It is stable enough that very small bits of C4 have been burned by soldiers in the field as an impromptu means to heat their rations. This is a bad habit to follow as the fumes of burning C4 are toxic and can poison the air in an enclosed space. Present production C4 contains taggants included in the explosive matrix. Taggants are very tiny plastic strips containing a unique code that identifies the specific production lot of the explosive. After the unlawful use of C4, taggants survive the blast sufficiently that the explosive can be traced back to its source. Taggants also help recover stolen C4.
