The European Agency for the Evaluation of Medicinal Products Veterinary Medicines Evaluation Unit

1. Propetamphos is an organophosphorus compound. Technical grade propetamphos consists of 4 isomers, 2 geometric (cis and trans) isomers and 2 optical (Sand R-)isomers. The cis form predominates as the active ingredient, usually exceeding 90% w/w of the technical material. From analogy with the chiral separation of propetamphos-oxon, cis-propetamphos is a racemate of equal proportions of the Sand R-enantiomers. The trans-form is generally present at less than 0.1% in the technical grade material.