ABSTRACT
In order to assess the ecotoxicological hazard potential of a foreign substance, the characteristic features of the substance must be determined, if at all possible in quantitative terms, as well as its environmental fate and possible effect. This chapter provides a definition of the most important parameters which are necessary to assess the ecotoxicological hazard potential of chemicals. Toxicological parameters are often used to assess the effects on human beings, although many of the actual tests are conducted on laboratory animals. The degree to which a parameter lends itself to immediate interpretation declines as the complexity of the level of organization increases, making it necessary to introduce additional, e.g. socio-economic, criteria to assess the environmental risk. The transition between physico-chemical parameters and fate parameters is flexible since the physico-chemical characteristics of a substance determine their fate in the environment, depending on the prevailing environmental conditions.
