Dissipation kinetics and risk assessment of iprovalicarb plus propineb fungicide in tomato under different agroclimates

Multi-location supervised field trials in India were conducted with a combination pesticide formulation (iprovalicarb 5.5% + propineb 61.25%, 66.75% WP) in tomato to study dissipation behavior at single (iprovalicarb 137.5 g a.i. ha(-1) + propineb 1531.25 g a.i. ha(-1)) and double (iprovalicarb 275 g a.i. ha(-1) + propineb 3062.5 g a.i. ha(-1)) dose. The samples were processed using a modified QuEChERS method for iprovalicarb and acid hydrolysis followed by carbon disulfide estimation for propineb and confirmation of their respective residues by LC-MS/MS and GC-MS. Both the fungicides in tomato fruits obey first-order kinetics irrespective of location and doses. Half-life (t(1/2)) values at all the four locations ranged from 1.08 to 4.67 days for iprovalicarb and 3.36 to 11.41 days for propineb in tomato. The Food Safety and Standards Authority of India (FSSAI) has set MRL of 1 mg kg(-1) for propineb, but no MRL is yet fixed for iprovalicarb. Using OECD MRL calculator, the calculated MRL for iprovalicarb and propineb was found to be 2 and 4 mg kg(-1), respectively. The hazard quotient (HQ) < 1, theoretical maximum daily intake (TMDI) < acceptable daily intake (ADI), TMDI < maximum permissible intake (MPI), percent acute hazard index (% aHI) <= 1, and percent chronic hazard index (% cHI) < 1 for both the fungicides indicated that the combination formulation will not pose any dietary risk and thus considered safe for human health.

Automated summary

Field trials in India showed that two fungicides used in tomato plants behaved according to first-order kinetics, with residues dissipation following a specific pattern regardless of dosage or location. While one of the chemicals had a set maximum residue limit (MRL) by the Food Safety and Standards Authority of India, the other did not. Calculated MRL values indicated that the combination formulation would not pose a dietary risk to human health.