In its refined form, Trinitrotoluene is very stable, and unlike nitriglycerin?, it is relatively insensitive to friction, blows or jarring. This means that it must be set off by a detonator?. It does not react with metals or adsorb water, and so is very stable for storage over long periods of time. It is readily acted upon by alkalies to form unstable compounds that are very sensitive to heat and impact.