Application for the Reassessment of a Hazardous Substance under ...

24 HUMAN EXPOSURE REPORTSThe APVMA (2008b) reported:―Hayes (1982) has described several cases of accidental occupationalpoisoning with dichlorvos. Two workers died after splashing a concentratedformulation on their bare arms and failing to wash it off promptly. In aserious but non-fatal case following dermal exposure, the victim developedslurred speech and drowsiness slightly more than 1.5 hours after theaccident. He collapsed suddenly after reaching a hospital but was saved byadministration of oxygen, artificial respiration, 15 mg atropine sulfate(mostly iv) and other supportive treatment. Spillage of a 3% dichlorvossolution in oil onto a man‘s lap resulted in severe poisoning. There was noeffort to remove the poison for about 30 minutes after the accident, when asuperficial wash was performed, followed by a bath at 90 minutespostexposure. The estimated dose of dichlorvos in this incident was 72mg/kg bw. In another case, a man spilled a smaller amount of the sameproduct onto his arm. He removed his shirt immediately and washed withsoap and water about 15 minutes later, but developed dizziness and nausea.“Bisby JA & Simpson GR (1975) An unusual presentation of systemicorganophosphate poisoning. Med J Australia 2; 394 – 395.A PCO was accidentally exposed to dichlorvos (1% solution in mineralspirit) whilst using a gasoline engine-powered knapsack mister. He wasfumigating a commercial premises and was wearing a singlet and overallsand a cartridge-type respirator. After 10 minutes he noticed a leak onto hisleft shoulder from a faulty seal and changed his overalls, but notundergarments, and placed a plastic sheet under the sprayer. During the day,he noticed increasing local irritation and burning in the contaminated skinarea. By the end of the shift he reported excessive tiredness, weakness,dizziness and breathing difficulties. After showering, the symptomsimproved although rapid shallow breathing lasted for 2 hours. He developedskin irritation, consisting of extensive areas of erythema and bulla. Whenwhole blood ChE was measured 3 days after exposure, it was 36% ofnormal but reached 51% after 5 days and 78% after a month.“Mathias CGT (1983) Persistent contact dermatitis from the insecticidedichlorvos. Contact Dermatitis 9; 217 – 218.A truck driver was exposed dermally to a liquid product containing 5%dichlorvos in 15% petroleum distillate and 80% trichloroethane, whichbecame spilled in vehicle. The next day he awoke with dermatitis of hisneck, anterior chest, dorsal hands and forearms. He also experienced afrontal headache, mild rhinorrhea, burning of the tongue and a bitter taste inhis mouth. Initial blood ChE activity level was in the ―low normal range‖. Arepeat assay 2 weeks later revealed activity in the ―high normal range‖. Thedermatitis resolved approximately 10 weeks after onset. Patch tests withdichlorvos in petrolatum were negative, so the cause of irritation waspresumed to be irritation rather than sensitisation.Dichlorvos reassessment – application Page 250 of 436