Acute and chronic toxicities of Irgarol alone and in combination with copper to the marine copepod Tigriopus japonicus

► Irgarol 1051 biocide is usually jointly used with Cu in antifouling paints. ► We investigated the toxicities of Irgarol-Cu mixtures to a marine copepod. ► Acute toxicities of the mixtures were simple additive as revealed by our results. ► The mixtures at high concentrations synergistically increased larval mortality. ► Hence it is vital to consider their joint toxic effect in the marine environment.