Exposure Prediction: A Proposal for a Program of Work. List of Participants. Limitations on the Calculation of Physicochemical Properties (J. Altschuh and R. Brnggemann). Photochemical Processes Contributing to Abiotic Degradation in the Environment (W. Kl pffer). Predictions of Chemical Transformation Rates of Organic Pollutants in Aquatic Systems (D. Macalady and R. Schwarzenbach). Quantitative Structure-Biodegradability Relationships for Predictive Purposes (P. Vasseur, P. Kuenemann, and J. Devillers). Volatilization of Chemicals from Water Bodies (P. Isnard). Mobility of Organic Chemicals in Soil Sorption Measurements and Modeling (W. K rdel, B. Oepen, and M. Klein). Transport and Behavior in Soil (M. Matthies). The Prediction of Fate and Exposure of Organic Chemicals in Aquatic Sediments (B. Harland, P. Matthiessen, and R. Murray-Smith). Prediction of Plant Uptake of Organic Xenobiotics by Chemical Substance and Plant Properties (I. Scheunert, R. Schroll, and S. Trapp). Bio concentration of Non-Polar Xenobiotics in Terrestrial Plant Biomass (C. Gaggi, D. Calamari, and E. Bacci). A Simple Model for Ranking the Hazard to Humans from Pesticide Vapors in Greenhouses (E. Bacci, D. Calamari, and C. Gaggi). Application of Simple Partitioning Models in Hazard Assessment (D. Calamari and A. DiGuardo). Prediction from the Past: Fate of Selected Persistent Chemicals in the Environment (J. Paasivirta). Linear Compartmental Models (J. de Greef). Ecotoxicology and Environmental Hazard Assessment in the Regulatory Framework of Chemicals Control in the EEC (P. Greiner).