Brisance is the shattering capability of a high explosive, determined mainly by its detonation pressure. The term can be traced from the French verb "briser" (to break or shatter) ultimately derived from the Celtic word "brissim" (to break). Brisance is of practical importance for determining the effectiveness of an explosion in fragmenting shells, bomb casings, grenades, structures, and the like. The sand crush test and Trauzl lead block test are commonly used to determine the relative brisance in comparison to TNT (which is considered a standard reference for many purposes).