Book excerpt: Today′s chemists need to know how hazardous the chemicals they work with are, and they want to understand the relationship between chemical and structural properties and toxicity. At the same time, modern society requires that chemists have this kowledge, as legislation makes the producers/users of chemicals responsible for any adverse effects. The book deals with the effects on both man and ecosystems. It stresses especially on the relationship between chemical structure and chemical properties/toxic effects and metabolic conversions. This is not just another book on toxicology. What makes this book special is that it is written from a chemical point of view. This textbook applies the basic principles of reactivity and reaction possibilities of organic compounds to metabolic reactions and living systems.