Health Canada has decided against completely banning outdoor use of two of the most common neonicotinoid active ingredients, but there will be new restrictions on their use as corn and soybean seed treatments.
After proposing a ban in 2018, the department published the final decisions for its special reviews of clothianidin and thiamethoxam on Wednesday.
The review process, which started in 2016, looked at the impact of the two pesticides on aquatic insects.
“Health Canada’s scientists have reviewed a large body of scientific information and concluded that a complete ban on neonicotinoid pesticides is not warranted. The additional risk mitigation actions announced in today’s final decisions, such as reducing the rate of applications and spray buffer zones, will address the risks posed to aquatic insects,” said the department on Wednesday.
Clothianidin and thiamethoxam are commonly used as seed treatments to protect canola, corn, and soybean seeds and seedlings from insect pests. Clothianidin-containing seed treatments include Poncho 600 FS, Prosper EverGol and Nipsit Suite. The list of products containing thiamethoxam includes Cruiser Maxx, Cruiser Vibrance, and Helix Vibrance. Both pesticides are also used in a wide variety of horticultural crops.
The decisions include the de-registration of several specific uses in horticultural crops, including onions, lettuce, and potatoes.
For field crops, there are new restrictions for the use of both neonicotinoids as seed treatments in corn and soybeans, but the department did not make any major changes for canola after reviewing additional water monitoring data from Western Canada, said an official with Health Canada’s Pest Management Regulatory Agency (PMRA).
As part of the decision on clothianidin, the maximum seed treatment rate for field corn will be reduced to 150 g a.i./100 kg seed, which will result in the cancellation of its labelled use for corn rootworm.
The thiamethoxam decision will also reduce the maximum seed treatment rate in field corn, to 200 g a.i./100 kg seed, resulting in the cancellation of its use for corn rootworm.
The seed treatment rate for thiamethoxam on soybeans will also be reduced to 30 g a.i./100 kg seed, which means it will no longer be labelled for use for bean leaf beetle, European chafer, soybean aphid, and wireworm.
The maximum number of foliar applications of thiamethoxam on soybeans and potatoes will be reduced to one per year.
The labels for products containing thiamethoxam and/or clothianidin will also include new or revised spray buffer zones around freshwater and terrestrial habitats.
Health Canada says the changes must be reflected on product labels within two years.
The president and CEO of CropLife Canada says the organization is encouraged by Health Canada’s decisions, but has some concerns about what it means for the horticulture sector.
“While we are still reviewing the full details of the special review decisions, we are pleased that the PMRA has affirmed that in many cases these important tools can be used without posing unacceptable risks to aquatic invertebrates,” says Pierre Petelle, in a statement shared with RealAgriculture. “Unfortunately, in some cases – specifically in the horticulture sector – many important uses of these products will be restricted, and in some cases, removed entirely. This will leave some growers without commercially viable alternatives to protect their crops and may jeopardize the viability of certain types of production in Canada.”
“It’s encouraging to see science prevail as the PMRA has changed its recommendations from what appeared in the proposed decision from 2018. Registrants and stakeholders provided PMRA with significant amounts of additional high-quality data during the consultation period, which appears to have helped the agency make a more informed, risk-based decision based on the best available real-world data,” continues Petelle.
Health Canada says it received more than 47,000 comments during the review process, as well as new studies and water monitoring data. Several new scientific papers on the topic were also published during the review timeline.
“The final special review decisions related to aquatic insects for clothianidin and thiamethoxam, originally targeted for fall 2020, were delayed until now due to the unprecedented volume of information received during consultation and the challenges of the COVID-19 pandemic,” said the department.
Health Canada will release its final re-evaluation decision for a third neonicotinoid — imidacloprid — later this year. The department is in the final stages of completing the review.
Editor’s note: This story was updated with quotes from Pierre Petelle, CropLife Canada.