One of the fundamental principles of green chemistry is to design chemical products that minimize adverse consequences to human health and the environment. While chemists have been designing molecules for 200 years to have a limitless range of commercial applications, there has been little or no attention focused on how to make commercial chemicals while avoiding hazards and toxicity. This book is the first to provide chemists with useful, practical guidance on how to minimize or avoid a wide range of hazards. Building on the insights gained from the pharmaceutical industry over the past 25 years on how to create desirable biological effects, the authors demonstrate how to avoid undesirable biological effects by design.