In accordance with the present invention there is provided an EC pesticidal formulation comprising: (1) at least one pesticide having melting point of 130 DEG C or less; (2) a plasticizer selected from the group consisting of rosin or rosin derivatives insoluble in water; (3) at least one surfacant; and (4) at least one polaric solvent completely or partially soluble in water to make up to one liter. This affords EC formulations which have low irritation and suprisingly improved biological activity to target species.