Efficiency of water rinsing for the decontamination of used pesticide containers

The efficiency of water rinsings for the decontamination of emptied pesticide containers was investigated in the period 1979–1981; nineteen formulations representing seven insecticides and two fungicides were studied. Following normal emptying procedures, the amount of retained pesticides ranged from a low of 0.06% to a high of 7.48%. By successively rinsing with volumes of water equal to one-tenth of the volume of the containers, as many as five rinses were required to remove 99% of the retained formulation. When containers were held in an inverted position and allowed to drain one minute prior to rinsing, three successive rinsings were sufficient for most formulations to remove 99% of the retained pesticide. Decontamination by rinsing was achieved most readily with water-soluble concentrates and wettable powders while flowable suspensions appeared to be the most difficult to remove.