Abstract
Risk assessment as a regulatory tool developed during virtually all of the 20th century. During this period there were several critical events such as the passage of the Food and Drug Acts of 1906 and 1938 and the publication of the National Research Council's report Risk Assessment in the Federal Government: Managing the Process, known as the “Red Book,” which defined the concepts and principles of risk assessment. This paper reviews the impact of some of the major events in the evolution of risk assessment and concludes with some speculation on the future.