Guidelines for Canadian Drinking Water Quality: Guideline Technical Document – Chlorpyrifos

Chlorpyrifos (C9H11Cl3NO3PS) is an organophosphorus insecticide used for the control of mosquitoes, flies, various crop pests in soil and on foliage, household pests and aquatic larvae. It is also used on sheep and cattle for the control of ectoparasites. The maximum acceptable concentration (MAC) for chlorpyrifos in drinking water is 0.09 mg/L (90 µg/L).