Many radical processes involve chain reactions or chain propagation with disproportionation and recombination occurring in the terminal step of the reaction. Terminating chain propagation is often most significant during polymerization as the desired chain propagation cannot take place if disproportionation and recombination reactions readily occur. Controlling termination products and regulating disproportionation and recombination reactions in the terminal step are important considerations in radical chemistry and polymerization. In some reactions (such as the one shown below)  one or both of the termination pathways can be hindered by steric or solvent effects.