The mechanism leading to the onset of the electrode effects is still under discussion in the literature. In this contribution it is proposed that the main mechanism responsible of the electrode effects is the formation of a gas film isolating the electrode. This gas film is formed because of a high population density of bubbles on the electrode surface. A simple model considering the bubble evolution as a stochastic renewal process is presented. By introducing some phenomenological relations, the model allows to evaluate the critical voltage and current density as well as the static current-voltage characteristics leading to the onset of the electrode effects. (C) 2004 Elsevier Ltd. All rights reserved.