Chlorpyrifos is a broad-spectrum organophosphate insecticide used to control insects in various settings. It is one of the most widely sold pesticides in Canada and is one of the few insecticides registered to manage certain important pests, including invasive alien species, and mosquitoes.
Chlorpyrifos is applied by growers and other certified users using ground equipment as a foliar, soil granular or drench application, and for some uses by aerial application. It kills insects by inhibiting the action of acetylcholinesterase, an enzyme that normally degrades acetylcholine, a “neurotransmitter” that is critical to the functioning of the nervous system.
The Pest Management Regulatory Agency of Health Canada released its proposed re-evaluation decision for Chlorpyrifos and its associated end-use products May 31, 2019 stating:
“Under the authority of the Pest Control Products Act and based on the evaluation of currently available scientific information, Health Canada is proposing cancellation of all uses of chlorpyrifos except those listed below, due to risks to the environment (aquatic biota, beneficial arthropods, birds and mammals) that were not found to be acceptable. These uses that are proposed for cancellation include almost all agricultural uses of chlorpyrifos.”
Only a small number of uses are acceptable for continued registration with required label changes:
• Standing water – temporary pools for
larval mosquito control
• Outdoor adult mosquito control
• Structural indoor and outdoor (non-residential)
• Outdoor ornamentals (container stock only) for control of Japanese beetle
larvae
• Greenhouse ornamentals
All products containing chlorpyrifos registered in Canada are subject to this proposed re-evaluation decision. This document is subject to a 90-day public consultation period, during which the public including the pesticide manufacturers and stakeholders may submit written comments and additional information to the PMRA. The final re-evaluation decision will be published taking into consideration zthe comments and information received.
