Tannerite is a binary compound explosive that consists of ammonium nitrate and aluminum powder. The ammonium nitrate component provides the fuel for the explosive, and the aluminum powder acts as a catalyst. The compound is stable under normal conditions, and because it ships as two components that are not independently explosive, no special permits or restrictions apply to its handling.
Commercial Tannerite's oxidizer consists of 200-mesh ammonium nitrate and between 0 and 15 percent ammonium perchlorate, but the exact ratio is a trade secret. It is the rapid decomposition of this compound that gives Tannerite most of its explosive force.
The catalyst is made from three different compounds. The bulk of the catalyst, around 90 percent of it, consists of 600-mesh dark-flake aluminum powder. The remaining 10 percent is split evenly between 325-mesh titanium sponge and 200-mesh zirconium hydroxide.
The makers of Tannerite mix the oxidizer and the catalyst separately and bundle them together for sale. The components are usually shipped with additional equipment useful in the final mixing process. This binary composition makes Tannerite, and its generic forms, attractive to safety- and legal-minded consumers. Stored separately, neither component is explosive. Even after mixing, Tannerite is stable, and it takes a high-energy impact, such as a rifle shot, to set off the charge.