Residue transfer and risk assessment of carbendazim in tea

Background: Carbendazim (methyl 1H-benzimidazol-2-ylcarbamate) residue in tea is a public concern. The large gap in the maximum residue limits (MRLs) for carbendazim in tea makes it difficult to conduct pesticide management. Therefore, a systemic evaluation of the residue and the health risk of carbendazim from the tea garden to brewed tea was investigated.

Results: The dissipation of carbendazim in tea shoots followed first-order rate kinetics, with a half-life (t_1/2 ) of 2.6 days. In green tea manufacturing, the carbendazim decrease of 2.81-26.74% was concentration-positive. The infusion factor of carbendazim was > 0.8 from dry tea to brewed tea and this was related to the brewing temperature and the size of the dry tea. All of the risk quotient values were significantly less than 1 in the evaluation of carbendazim residue in real tea samples and MRL.

Conclusion: Residue transfer and risk assessment were evaluated for carbendazim in green tea. Carbendazim revealed a less persistent nature in tea plants. Green tea processing played a small role in decreasing carbendazim residue. Almost all of the carbendazim in dry tea leached into the brewed tea. However, the possible health risk induced by residual carbendazim in green tea was not significant. These findings are helpful when reconsidering the MRLs of carbendazim in tea. © 2018 Society of Chemical Industry.