DECONTAMINATION OF INSECTICIDES FROM VARIOUS SURFACES

Abstract:
We explored decontamination measures which would minimise risk of exposure. Decontamination and cleaning methods were chosen according to the structure of treated surface area and the properties of the active compound. Commercial cleaning agents were used to decontaminate areas treated with insecticides under standard conditions. Insecticides were cyfluthrin, b-cyfluthrin, propoxur, and phoxim, which were used in formulations such as microencapsulated suspension, suspension concentrate, macro emulsion concentrate and emulsifiable concentrates. Successful decontamination was indicated by analytical procedures and biological assay with Musca domestica. Greatest reduction was achieved with the micro-encapsulated formulation, then suspension concentrate, macroemulsion concentrate, and emulsifiable concentrates, using high pressure extraction methods. Sealed, waterproof surfaces such as glazed tiles can be more than 99% decontaminated, mainly by the high-pressure extraction; open-pored, water-sensitive surfaces such as carpet with microencapsulated suspension and suspension concentrate formulations can be 90% decontaminated by high-pressure extraction. Decontaminants affect the decontamination result in the high-pressure extraction process by1 - 2 %, the active ingredient is of secondary importance. In manual decontamination of small areas with abrasive pads and scrubbing brushes, the influence of the decontaminant on the decontamination result was increased. Alkaline cleaners containing solvents led to the greatest reduction with manual decontamination. PVC could be decontaminated up to 99% using scouring; 98% of the macro-emulsion formulated cyfluthrin and 99% of other formulations could be removed from uncoated PVC. Decontamination is influenced by the surface, the method and the formulation.