Typically, the boom factor is proportional to the typical safety distance one experiences it. Flash bangs and grenades? Probably within throwing distance. RPGs and anti-tank Gustavs? A couple of yards away at least.
The only exception? Bangalore Tubes - evil little mfkers…. They look harmless, thin little tubes, barely thicker than strippers’ dancing pole, but daisy chain them together, set it up, barely have time to get away before they blow up with hell of a concussion and rain all types of crap on you.