Statement on oral toxicity of endosulfan in fish

Endosulfan is a pesticide currently not authorised in the European Union and regulated as an undesirable substance in animal feed. The European Food Safety Authority (EFSA) was asked by the European Commission to assess recent information on the toxicity of endosulfan in fish and, if necessary, to update its opinion on endosulfan as an undesirable substance in animal feed, adopted on 20 June 2005 by the Scientific Panel on the Contaminants in the Food Chain (CONTAM Panel) and updated on 10 April 2006. The CONTAM Panel assessed six recent publications on exposure of Nile tilapia and Atlantic salmon to endosulfan via feed. Morphological changes in the liver were observed in Nile tilapia following 35 days of exposure to ≥ 0.001 mg/kg endosulfan in feed in tanks. However, such effects were not observed in Atlantic salmon exposed at 0.005 – 1 mg/kg endosulfan. Histological changes were observed in the intestine in Atlantic salmon following 49 or 112 days of exposure to ≥ 0.005 mg/kg endosulfan in feed in tanks, without a clear dose-effect relationship. Such changes in the intestine were not seen when Atlantic salmon were exposed for 95 days to up to 0.1 mg/kg endosulfan via feed in open sea-cages. Although a different sensitivity of Nile tilapia and Atlantic salmon to endosulfan could not be discounted, the CONTAM Panel noted that differences in the experimental conditions applied, leading to possible contamination of water with endosulfan, could also have influenced the results. The CONTAM Panel concluded that the recent information on toxicity of endosulfan in fish does not change the conclusions on toxicity in fish drawn in its previous opinion. The CONTAM Panel noted that further appropriately designed studies on oral toxicity in fish are needed to confirm the possible differences between fish species in sensitivity to endosulfan.