ABSTRACT
Both understanding and evaluating chronic toxicity of chemicals are essential to assessing their environmental hazards and making environmentally sound management decisions. Because of the large number and variety of industrial, agricultural and home-use chemicals released in the U.S. annually and the high cost and effort required for chronic tests, resources are often insufficient to obtain experimental information about long-term environmental impacts for all potentially hazardous chemicals. In comparison, acute tests are less costly and require less time for completion and, for these reasons, there is an abundance of acute toxicity data for numerous chemicals and organisms. Also, there are procedures for extrapolating effects data within classes of chemicals sharing similar chemical structures.
