This work offers an analysis of the biological processes mediated by free radicals, from a toxicological point of view, providing easy access to information in an integrated, coherent presentation. The chemistry and biochemistry of all principal types of radical are explained, and the multiple forms in whch radicals participate in living organisms are investigated.;This work should be of use to biochemists, pharmacologists, pharmaceutical researchers, food scientists and technologists, nutritionists, toxicologists, chemists, biologists and graduate students in these disciplines.