Development and standardisation of an ecotoxicological test method for the environmental risk assessment of genetically modified plants

Prior to releasing a genetically modified plant (GMP) into the environment and placing it on the market in the European Union (EU), an environmental risk assessment (ERA) according to EU Directive 2001/18/EC has to be performed. Current testing of the effects of GMPs on non-target organisms is mainly based on ecotoxicological test methods that were developed for the assessment of chemical substances. This approach does not fully comply with Directive 2001/18/EC, which demands a case-specific ERA. According to Annex II of the Directive, a ‘case’ is defined as a combination of the parent organism, its genetic modification, and the possible receiving environment related to the intended release and use of the genetically modified plant. As the standard test organisms used for the assessment of chemical substances do usually not occur in the receiving environment of GMPs, they cannot be considered adequate. Using an ecology-based selection approach, the test species should be selected from organism groups that are relevant to the receiving environment and to the various exposure pathways. In addition, different taxonomical and physiological groups should be covered. At the same time, the selected species should be easy to handle for standardised testing in the laboratory.

Hence, the aim of this project was to develop and standardise a laboratory ecotoxicological test specific for the environmental risk assessment of genetically modified plants. This aim was reached in three steps. First, the black fungus gnat Bradysia impatiens (Sciaridae: Diptera) was identified as a suitable test species, and its mass rearing in the laboratory was established. The second work step comprised the actual development and trial of the developed test method, which meets the specific characteristics of the assessment of GMPs. In the third and final work step, the method was described in a draft guideline according to the specifications of the OECD.