The potential-independent value that is approached by an adsorption current as the rate of reduction or oxidation of the electroactive substance is increased by varying the applied potential. The terms adsorption current and limiting adsorption current should not be applied to faradaic currents that have been increased or decreased by adding a non-electroactive surfactant to a solution containing an electroactive substance, nor to apparent waves resulting from the effect of adsorption or desorption on double-layer currents.