ABSTRACT
Extrapolation methods are used for various types of risk assessment. Reviews on the issue of extrapolation demonstrated that indeed a plethora of extrapolation methods exists. The diversity of existing extrapolation techniques also relates to the types of extrapolation problems. Extrapolation can consist of range extrapolation, implying intra- or extrapolation using an available data set. The diversity of extrapolation techniques relates to the diversity of technical solutions that have been defined in the face of the various extrapolation problems. The guidance discusses issues that are relevant to making systematic use of the available methods, such as the concept of tiering, and the ordering of extrapolation methods according to their scientific principles and expected precision. The development of an extrapolation scheme for a specific problem may frequently need to start from a regulatory perspective, the set of extrapolation methods is already clearly defined for a given assessment problem. The basic features of ecological risk assessment schemes are very similar throughout the world.
