UV–visible irradiation of thiophanate-methyl (TM) led to nine photoproducts.
HPLC coupled with ultra-high resolution FTICR-MS allowed byproducts characterization.
TM and one photoproduct were detected in peel and flesh of fruits treated with TM.
In vitro tests showed that irradiation increases the global ecotoxicity of TM.
In silico tests permitted to attribute the ecotoxicity enhancement to a photoproduct.