The regulation of risk is a preoccupation of contemporary global society and an increasingly important part of international law in areas ranging from environmental protection to international trade. This book examines a key aspect of international risk regulation - the way in which science and technical expertise are used in reaching decisions about how to assess and manage global risks. An interdisciplinary analysis is employed to illuminate how science has been used in international legal processes and global institutions such as the World Trade Organization. Case studies of risk regulation in international law are drawn from diverse fields including environmental treaty law, international trade law, food safety regulation and standard-setting, biosafety and chemicals regulation. The book also addresses the important question of the most appropriate balance between science and non-scientific inputs in different areas of international risk regulation.