PMRA Review Reveals Clothianidin and Thiamethoxam Do Not Pose Risk to Aquatic Invertebrates

April 01, 2021

On March 31 the Pest Management Regulatory Agency (PMRA) released their long awaited Special Review Decisions for Clothianidin and Thiamethoxam Risk to Aquatic Invertebrates, and affirmed that in many cases these tools can be used without posing unacceptable risks to aquatic invertebrates.

This decision is a change from the 2018 proposed re-evaluation decision to cancel all outdoor agriculture uses of these products due to concerns over the potential risk to aquatic invertebrates that was based on conservative modelling. Due to an extensive amount of data that was made available to the PMRA after the publications of the proposed re-evaluation decision, they were able to come to a more informed, risk-based decision that is based on the best available real-world data.

This re-evaluation decision will impact thiamethoxam use for Saskatchewan growers, as rates will be reduced to 30 g a.i./100 kg seed for soybeans. This will result in the cancellation of the use for bean leaf beetle, European chafer, soybean aphid, and wireworm. The number of foliar applications of thiamethoxam is reduced to one per year on dry beans and soybeans.

SPG has been involved throughout the PMRA review process, collaborating with the other provincial pulse organizations and Pulse Canada to formulate an in-depth Canadian Pulse Industry Stakeholder submission in response to the proposed decisions for clothianidin and thiamethoxam to cancel all outdoor agriculture uses. SPG also funded water monitoring data to help address critical gaps in the original data set. This new water monitoring data was a critical piece to the change in the proposed decision by PMRA. 

Pulse Canada will continue to review the full details of the final special review decision documents.