Outline and criteria for evaluating the safety of new chemicals

Abstract

Risk assessments for chemicals manufactured in large quantities, used by many people, and disposed of broadly into the environment require a systematic process with emphasis on scientific fudgments, specific criteria for decision making, and an overall process for ensuring that human and material resources are used effectively and efficiently. A risk assessment process incorporating these features consists of careful prework in which the physical, chemical, and biological characteristics of the material are organized from known information or predicted from structural considerations as well as information related to the intended manufacture, distribution, use, and disposal. Interrelated programs involving a number of scientific disciplines are then developed for human and for environmental risk assessments. Both of these programs rely on the development of increasingly refined relationships between predicted doses or exposure and biological effects in animal models. Predictive tests for environmental fate and concentrations and for biological effects are selected and conducted progressively. Specific decision criteria based on comparisons of predicted exposures with biological effects data are used to decide when enough testing has been conducted to make a risk assessment. The application of these guidelines to three example chemicals is provided to illustrate the decision-making process.