Update on the Neonicotinoid Pesticides

30 September 2020
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This document provides a progress report on Health Canada's Pest Management Regulatory Agency's (PMRA) ongoing assessments of the neonicotinoid insecticides (see previous update on the Neonicotinoid Pesticides in 2020). The assessment of this group of insecticides is extremely complex and multi-faceted; a status update for each aspect of the assessments follows.


Neonicotinoids are a group of pesticides used in agriculture to protect crops from various insects. They are also used for other purposes, including killing insects in homes, controlling fleas on pets, and protecting trees from invasive insects such as the Emerald Ash borer. There are three main neonicotinoids currently approved for agricultural use in Canada: imidacloprid, clothianidin, and thiamethoxam.

Health Canada is considering many components as they relate to the registration of this group of pesticides including:

The following sections provide an update on the status of each of these components.

Pollinator Incident Reports

Declines in honeybee and other pollinator populations have generated considerable scientific and public interest both in Canada and internationally. The available science suggests that multiple factors acting in combination may be at play, including loss of habitat and food sources, diseases, viruses and pests, and pesticide exposure.

In 2012, Health Canada began receiving large numbers of bee incident reports. Health Canada, in collaboration with many stakeholders, implemented risk reduction measures to minimize exposure to pollinators. With these risk mitigation measures in place, Health Canada saw a significant decrease in the number of incidents reported. The number of bee incidents in 2014, 2015 and 2016 were 70-80% lower than in 2013 and a further decrease in the number of incidents was reported in 2017–2019. Health Canada continues to monitor the bee incident reports.

Pollinator Assessments: Thiamethoxam, Clothianidin, and Imidacloprid

A. Completed work to date:

In 2012, in response to new research and the establishment of a new North American pollinator risk assessment framework, in cooperation with the United States Environmental Protection Agency (USEPA) and the California Department of Pesticide Regulation, Health Canada initiated pollinator focused re-evaluations of the three neonicotinoids (thiamethoxam, clothianidin, and imidacloprid). Health Canada completed the three pollinator re-evaluations and published its decisions on 11 April 2019.

In order to protect pollinators, Health Canada cancelled many uses of neonicotinoids on crops that bees find attractive, such as orchard trees, and prohibited spraying of some crops, such as berries and fruiting vegetables, before or during bloom. Seed treatment uses were found to be acceptable; however, Health Canada required the addition of label statements for all cereal and legume crops to minimize exposure of pollinators to dust during planting of treated seeds. The implementation of these decisions is currently underway. Accordingly, both registrants and retailers have until 11 April 2021 to transition to selling the product with the newly amended labels. Similarly, users will also have until 11 April 2021 to transition to using the newly amended labels.

B. Work to be completed (Squash bee special reviews):

Health Canada initiated special reviews of clothianidin, imidacloprid and thiamethoxam products that are registered for use on cucurbits such as pumpkin, squash and watermelon. The aspect of concern for these special reviews is the potential environmental risk related to a specific species of ground-dwelling bee, squash bees (Peponapis pruinosa).

Health Canada plans to complete the proposed special review decisions (related to squash bees) in Spring of 2021, based on the available information.

Cyclical Re-evaluation: Imidacloprid
Aquatic Special Reviews: Clothianidin and Thiamethoxam

A. Completed work to date:

On 23 November 2016, Health Canada published for consultation a proposed re-evaluation decision for imidacloprid. On 15 August 2018, Health Canada published two proposed special review decisions, for clothianidin and thiamethoxam, examining the risks to aquatic invertebrates. All three proposals indicated that these substances have been measured at levels that are expected to be harmful to aquatic insects. Therefore, Health Canada proposed to phase out all the agricultural and a majority of other outdoor uses of imidacloprid, as well as all outdoor uses of clothianidin and thiamethoxam to protect the environment.

B. Current status:

Health Canada is reviewing a substantial amount of new information that has since been received. This included comments from the public, pesticide registrants, provinces, and an unprecedented amount of new water monitoring data from various stakeholders such as Agriculture and Agri-Food Canada's water monitoring working group and from the provinces. These new data are of high quality and provide a much clearer picture of the levels of neonicotinoid pesticides being detected across Canada. The information and data provided by the various working groups of the Multi-Stakeholder Forum on Neonicotinoids has proven to be crucial in Health Canada's assessments. In addition, Health Canada is also considering new information that is being published in scientific papers on neonicotinoids. This new information will be incorporated in the risk assessment to ensure that the upcoming decisions reflect the current scientific knowledge.

C. Revised timeline for completion:

In January 2020, Health Canada had committed to reporting its findings on the aquatic special reviews of clothianidin and thiamethoxam and the general re-evaluation of imidacloprid by Fall of 2020. However, due to the vast amount of new information received, and the measures taken related to the COVID-19 pandemic, the scientific reviews have encountered delays. Health Canada is now expecting to publish these decisions (aquatic special reviews of clothianidin and thiamethoxam, and the general re-evaluation of imidacloprid) in Spring 2021.

Cyclical Re-evaluations: Clothianidin and Thiamethoxam

A. Current status:

Full cyclical re-evaluations of clothianidin and thiamethoxam were initiated in 2016 to assess their value, as well as human health and environmental risks other than impacts on pollinators and aquatic invertebrates. As mentioned above, the assessment of the impacts on pollinators was completed in 2019 and the assessment of the impacts on aquatic invertebrates is being considered in the special reviews.

B. Timeline for completion:

These cyclical reviews are currently under way, and proposed decisions will follow the final decisions for the special reviews of thiamethoxam and clothianidin on the risks to aquatic insects. Health Canada is now expecting to publish the proposed cyclical re-evaluation decisions of clothianidin and thiamethoxam in Spring 2022.

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