Aquatic Fate Assessment Method for Consumer Product Ingredients in Japan. C. E. Cowan, A. Yamamoto, D. C. McAvoy, and E. Namkung, The Procter & Gamble Company, Ivorydale Technical Center and Procter & Gamble Far East, Inc., Japan Technical Center
Environmental regulations as well as the policies of many multi-national companies require that the proposed commerce and use of new substances and the current use of existing substances be safe for the environment. To determine safety, an environmental risk assessment is conducted which evaluates the likelihood that adverse ecological effects are or may be occurring as a result of exposure to a substance. To conduct this environmental risk assessment, fate and effects assessments in environmental compartments that receive discharges of the substance are required. The fate assessment involves developing an understanding of what ultimately happens to a substance when it is released into the environment and predicting the environmental concentration (PEC) to which organisms in the environment will be exposed. A fate assessment approach was developed for Japan using information on the routes by which consumer products reach Japanese aquatic environments, and data on Japanese environmental characteristics. First, the dilution factor approach was parameterized for all of Japan. Second, a river model was developed using data for the Tamagawa River to illustrate how to estimate the concentration of a substance in a river as a result of multiple discharges of treated and untreated wastewater. This approach is illustrated using data on linear alkylbenzene sulfonate, LAS, a major ingredient in many laundry and cleaning products. Finally, the predicted environmental concentrations for LAS are used to conduct a preliminary risk assessment for Japan.