Semtex is a plastic explosive that was originally developed in Czechoslovakia in the 1950s. It is known for its high stability and effectiveness, making it a popular choice for military and demolition applications. Semtex is often used in construction and mining, as well as in military operations due to its ability to be molded into various shapes. The explosive is composed of a mixture of RDX and PETN, which are both powerful explosive compounds. Semtex gained notoriety in the 1980s and 1990s when it was used in various terrorist attacks, leading to increased scrutiny and regulation of its production and distribution.