Residues of trichlorphon (neguvon) in milk after dermal application to cattle

Abstract

The probability that trichlorphon may be used t o control warbles in dairy cattle has raised the question of whether milk from treated animals will contain any harmful residues. Results from bioassays show that, when applied as a dermal wash a t a maximum of 2 pints of 2'36 solution or I pint of 4% solution per animal, the level of insecticide present in the milk does not a t any time exceed 0.4 p.p.m. and if more than 6 h. has elapsed after treatment, the level is generally about 0.1 p.p.m. I t is considered that this level does not present a hazard to any consumer. The presence of open warble holes does not materially affect the amount of trichlorphon secreted in the milk. Introduction00-Dimethyl (I-hydroxy-z,z,z-trichloroethy1)phosphonate is a water-soluble insecticide commonly known in Britain as ' trichlorphon '. I t has also been known as ' Bayer L 13/59 '