Book excerpt: This text explores nonbranching reactions, including in-depth information on the inhibitors of free radical polymerisation and the mechanisms of antioxidants on oxidationprocesses. Auto-initiated chain reactions are also explored, with detailed descriptions on the kinetics, mechanisms, and inhibition of the autoxidation of organic compounds, A special chapter deals with the synergism of antioxidant actions. The theory of chain-branching reactions is investigated, and a large amount of new experimental data concerning the use of chemical additives to regulate combustion processes is also presented, including the mode of chain thermal explosion.