The health risk to the agricultural worker using pesticides is important for registration procedures since during mixing, loading and application he or she handles undiluted as well as diluted pesticide formulations. Furthermore, exposure may occur during daily activities in the crop (e.g. harvesting). Possible exposure may reach levels that lead to excessive health risks depending on the toxicity of the pesticide. In such cases measures to ensure safe handling have to be prescribed. In the present paper the published data, based on exposure occurring in agricultural practice, are considered for extrapolation to obtain surrogate exposure levels for risk assessment in registration procedures. The criteria necessary for the input of exposure data in data-bases, and the scope for extrapolation and its drawbacks, will be discussed. The various exposure models that have been described will be discussed and compared, and illustrated with a few cases.