Bhc (benzene Hexachloride) Formulations

Experience in Queensland has shown that when crude BHC is refined to yield products containing higher proportions of the gamma isomer, the insecticidal persistence of the BHC in soil is decreased. This process also diminishes the specific toxicity of BHC to the soldier fly pest, Alfe~nzetopon.ia rubriceps (Macq.). I t also decreases the potential phytotoxicity, since less total BHC is required to provide any stipulated amount of gainnla isomer. Unless these factors are given due consideration, experiments with BI-IC against pests cannot be adequately designed, and unless the nature of the BKC used is reported readers cannot properly evaluate the results and claims published by workers. Examples are given of adequate descriptions of BHC forinulations, and reference is made to the legislative control of sales of BHC formulations in Queensland.