The toxicological monographs and monograph addenda contained in this volume were prepared by a WHO Core Assessment Group that met with the FAO Panel of Experts on Pesticide Residues in Food and the Environment in a Joint Meeting on Pesticide Residues (JMPR) in Rome, Italy, on 9-18 September 2008. Six of the substances evaluated by the WHO Core Assessment Group (azoxystrobin, chlorantraniliprole, mandipropamid, prothioconazole, spinetoram and spirotetramat) were evaluated for the first time. Six compounds (buprofezin, hexythiazoz,, flusilazole, procymidone, profenofos) were re-evaluated within the periodic review programme of the Codex Committee on Pesticide Residues (CCPR). Reports and other documents resulting from previous Joint Meetings on Pesticide Residues are listed in Annex 1.