[en] It has been shown rigorously that, within the diffusion model, the reduction of the molecular yield by competitive scavenger reaction always follows a square-root law in the limit of small scavenger concentration, and not a cube-root law. The error of earlier demonstration of the cube-root dependence using diffusion kinetics by Byakov has been traced to several reasons. The most important reason is the neglect of competition between scavenging and recombination reaction within the characteristic time t₁ which, in the limit of small concentration of the scavenger, proceeds to infinity