Recombinant DNA technology has found many interesting applications within the area of plant breeding. Food crops have been developed with altered characteristics like improved pest and disease resistance and prolonged shelf-life. Although the registration of new varieties of existing crop plants has not resulted in adverse effects in humans, the conventional assessments by plant breeders were not considered to be sufficient to ensure food safety of the genetically modified (GM) crop plants. Therefore, the European Community has established a legal framework for the introduction of novel foods with the Regulation on Novel Foods and Novel Food Ingredients (EC/258/97), which came into force in May 1997. The accompanying guidelines for the safety assessment of GM foods are centred around the so-called ‘Concept of Substantial Equivalency’. According to this principle, the evaluation should be based on a comparison with conventionally bred products, assuming that these traditional foods have a long history of safe use. The guidelines indicate the type of agronomical, (bio)chemical and nutritional parameters to be considered for the safety assessment and deal with three main food safety issues:

• the nutritional and toxicological consequences of inserted gene products;

• the allergenicity of expressed proteins and novel foodstuffs; and

• the potential of pleiotropic (unintended) effects in the host organism due to the insertion event.

This chapter describes existing methods for the safety evaluation of transgenic crop plants in general.