In order to assess the lifetime hazard of ingestion exposure of man to new substances a steady state model has been constructed called Uniform system for the Evaluation of Substances. In this risk assessment system emission concentration of organic substances in water and soil are linked to exposure concentration for humans and predators. In this prototype model the route of the compound from the air into the plant has not been included. In this report several models describing deposition on and uptake of aerosols and gaseous substances into plants have been described. In most models described here deposition and uptake are combined. In USES the deposition part has already been described and for implementation in the USES model the deposition part of these models can be left out. For implementation in USES (1992) the aerosol model of McKone and Ryan (1989) seems most appropriate. This model estimates a partition coefficient for all aerosols with a particle size < 5 mum. For gaseous substances the model of Riederer (1990) seems most appropriate, which combines physical-chemical properties of the substance and the fugacity principles of Mackay and coworkers.