ABSTRACT
A classification of the ecotoxicological hazard potential is mandatory for the registration or notification of pesticides and environmental chemicals, respectively. This chapter provides examples of some older classification systems, which are limited to effect comparisons. In addition to identifying and monitoring the fate and effects of foreign substances, ecotoxicology must assess the potential hazard of the foreign substances to environment based on scientific criteria. Evaluation goes one step further than assessment in that it takes additional — e.g. economic — criteria into consideration. The first step of the assessment process is devoted to formulating the problem, in other words to “hazard identification”. In the European Union, the concentration at which there are no longer any observable effects on ecosystem level is estimated on basis of several specific NOEC data. The EPA has been considering an “Ecological Risk Assessment Triad”, in which site- and ecosystem-specific exposure data from the respective compartment are compared with the data collected in monitoring surveys in the field.
