Scientific opinion on an application by Syngenta (EFSA-GMO-DE-2009-66) for placing on the market of herbicide tolerant and insect resistant maize Bt11 * MIR162 * MIR604 * GA21 and sub combinations independently of their origin for food and feed uses, import and processing under Regulation (EC) No 1829/2003

The EFSA GMO Panel previously assessed the four single events combined to produce a four-event stack maize Bt11 * MIR162 * MIR604 * GA21 and did not identify safety concerns. In this opinion, the EFSA GMO Panel assesses the four-event stack maize and all its subcombinations independently of their origin. No new data on the single events, leading to modification of the original conclusions on their safety, were identified. The molecular, agronomic, phenotypic and compositional data on the four-event stack maize did not give rise to safety concerns and there is no reason to expect interactions between the single events impacting on the food and feed safety of the four-event stack maize. Considering the routes of exposure and limited exposure levels, the Panel concludes that this four-event stack maize would not raise safety concerns in the event of accidental release of viable grains into the environment. The EFSA GMO Panel concludes that the four-event stack maize is as safe and as nutritious as its conventional counterpart in the context of its scope. Among the 10 subcombinations, four have been assessed previously and no safety concerns were identified. For the remaining six subcombinations, the EFSA GMO Panel followed a weight-of-evidence approach, and concluded they are expected to be as safe as the four-event stack maize. For some subcombinations that could be produced by conventional crossing through targeted breeding approaches, little or no specific data were submitted, giving rise to uncertainties due to data gaps. To reduce these uncertainties and to confirm assumptions made for the assessment of these subcombinations, the EFSA GMO Panel recommends that the applicant collate relevant information, if these subcombinations were to be created via targeted breeding approaches and commercialised in the future. In this case, this information should focus on expression levels of the newly expressed proteins.