The fate of a substance is governed by the distribution of the substance between soil, water, air, and biota, and the concentration of the substance and its altered forms existing over time in these media. As vegetable food forms a major part of the diet of human beings, and also of cattle, the contamination of plants will have a large influence on the total daily intake of a substance. In this report the application of soil-plant transfer factors is investigated. The main goal was to find sufficient experimental data in the available literature, if possible adjusted for differences in experimental design, which could be used to evaluate the currently applied method in the Uniform System for the Evaluation of Substances (USES). In this method, concentrations in root and stem of the plant are estimated on the basis of an empirical relationship with the octanol-water partitioning coefficient. It was concluded that the root concentration factor as applied in USES is an appropriate instrument for the estimation of residues in roots, whereas the application of the stem concentration factor is insufficient for the purpose set in USES. Consequently for above-ground plant parts other approaches need to be explored which can be applied in the general risk assessment of substances.