Persistence of fipronil and its risk assessment on cabbage, Brassica oleracea var. capitata L.

Persistence of fipronil in cabbage was studied following three applications of Jump 80 WG at 75 and 150 g a.i. ha−1 at 7 day interval. The average initial deposits of total fipronil (fipronil and its metabolites) were 1.226 and 2.704 mg kg−1 on the heads following 3rd application of fipronil at single and double the dosages, respectively. Desulfinyl was found to be the main metabolite followed by sulfone and sulfide. Metabolite amide was not detected in cabbage samples. Half-life periods for fipronil were found to be 3.43 and 3.21 day at single and double the application rates, respectively. Risk assessment of fipronil to the consumers was calculated on the basis of per capita 80 g consumption of cabbage and comparing it to its ADI for an adult of 55 kg which was found to be less than its ADI on 10th day at both the dosages.

► Half-life of fipronil was observed to be 3.43 day when applied at 75 g a.i. ha−1.
► Desulfinyl was the dominant metabolite followed by sulphide and sulfone.
► Amide metabolites were not detected in cabbage and soil.
► A waiting of 10 day is suggested for safe consumption of cabbage heads.