[Anthony]

Using energy values for TNT equivalence assumes perfect shockwave formation and all fuel being consumed in the initial blast, both of which are unlikely to be the case (most dust explosions are actually deflagration, not detonation, and continue burning for some time after the initial blast). For example, a tanker truck explosion involves around twenty tons of flammable material with a heat of combustion about ten times the detonation energy of TNT, but it isn't equivalent to a tactical nuclear weapon.