Dissipation and risk assessment of forchlorfenuron and its major metabolites in oriental melon under greenhouse cultivation

Forchlorfenuron is a widely used plant growth regulator. The uptake of forchlorfenuron and its major metabolites poses a potential risk for human health. However, little is known about the dissipation of forchlorfenuron and its major metabolites in agricultural food. In this study, the metabolite 4-hydroxyphenyl-forchlorfenuron was first identified in oriental melon, which exhibited the highest level of residues of 4.42–5.12 μg/kg on the 4–7th days after application. Forchlorfenuron was found to be dissipated rapidly in melon at the recommended application rates, with half-lives ranging from 1.20 to 1.33 days. The rate of dissipation of 4-hydroxyphenyl-forchlorfenuron was greater than that of metabolism from forchlorfenuron in the oriental melon. However, the other metabolite, 3-hydroxyphenyl-forchlorfenuron, was not detected in oriental melon. The risk assessment showed that the acute and chronic dietary exposure risks of forchlorfenuron in oriental melon were 0.0011–0.0037% and 0.06–0.12%, respectively, suggesting little health risk to Chinese consumers. [Display omitted] •A rapid method for the simultaneous determination of forchlorfenuron and its major metabolites in melon was established.•The metabolite 4-hydroxyphenyl-forchlorfenuron was first identified in melon.•The dissipation rate of 4-hydroxyphenyl-forchlorfenuron was greater than the metabolic rate of forchlorfenuron.•Dietary exposure risks associated with forchlorfenuron in melon in China are not a health concern.