Maximum residue limit and risk assessment of beta-cyfluthrin and imidacloprid in combination formulation on Tomato (Lycopersicon esculentum)

Division of Agricultural Chemicals; LBS Building, Indian Agricultural Research Institute, Pusa, New

Delhi-110 012, India

Manuscript received online 17 May 2012, revised 08 August 2012, accepted 03 October 2012

Field and laboratory experiments were carried out to study the persistence and dissipation of beta-cyfluthrin and imidacloprid in combination-mix formation on tomato. Initial deposits of beta-cyfluthrin ranged from 1.224 to 2.133 mg kg^-1 and imidacloprid ranged from 1.447 to 2.383 mg kg^-1 in tomato. Beta-cyfluthrin residues dissipated quickly and attained the below detectable level by 10 to 15 day. Imidacloprid residues are dissipated to below detectable limit (BDL) within 15 days after application. The Theoretical Maximum Residue Contribution (TMRC) values of initial deposits were quite low (beta-cyfluthrin, 0.245-0.427 mg person^-1 day^-1; imidacloprid, 0.289-0.477 mg person^-1 day^-1) than the maximum allowable concentration value (beta-cyfluthrin, 1.0 mg person-1 day-1; imidacloprid, 3.0 mg person^-1 day^-1). Based on the residue data, the Maximum Residue Limit (MRL) of 0.5 mg kg^-1 is proposed for both beta-cyfluthrin and imidacloprid in tomato fruits under Indian conditions. Assuming if this MRL is fixed, the Theoretical Maximum Daily Intake (TMDI) was calculated as 0.1 mg person^-1 day^-1 and % ADI (Acceptable Daily Intake) value of 10 and 3.33% also ensures the safety of beta-cyfiuthrin and imidacloprid respectively. A waiting period of 3 days before harvest could ensures a sufficient margin. of safety without any risk to human health.