Two novel indices for quantitatively characterizing the toxicity interaction between ionic liquid and carbamate pesticides

► We develop two novel mixture toxicity indices, concentration addition index (CAI) and effect addition index (EAI), to quantitatively characterize toxicity interaction. ► Four binary mixture systems containing ionic liquid and carbamate pesticides are designed by using uniform design concentration ratio ray approach. ► Four typical methods, toxic unit (TU), isobologram, model deviation ratio (MDR), and effect residual ratio (ERR), are employed to evaluate toxicity interaction. ► The two classical methods, toxic unit (TU) and isobologram, are extended at multiple effects.