It is found that, if the off-shell form factors for nucleons can be invoked to ensure current conservation during the instantaneous absorption of the four-momentum transfer by a particular constituent nucleon, the nuclear current in the resultant impulse approximation is conserved in the operator sense. It is also found that, if we start with a relativistic second-quantized operator representation of a given current, a precise definition can be ascribed to the nonrelativistic impulse approximation.