Changes to the registration of thiamethoxam pesticides

All pesticides used in Canada must be registered under the Pest Control Products Act. Pesticides are re-evaluated to ensure that they continue to meet health and environmental requirements. Re-evaluation may result in the revocation of a product or product uses. Health Canada may also request changes to a product's label, including risk mitigation measures, use sites and application methods.

Thiamethoxam is a neonicotinoid insecticide used on various crops, and for seed treatment. The key elements of the two decisions regarding the active ingredient thiamethoxam, published respectively on April 11, 2019, and March 31, 2021, are summarized below.

Label changes for thiamethoxam pesticides

Cancelled uses

As of April 11, 2021

Stop the following uses:

• Foliar and ground application on outdoor ornamental crops
• Ground application on berries, cucurbits and fruiting vegetable crops
• Foliar application in orchards

As of March 31, 2023

Stop the following uses:

• Soil drench application on potatoes
• Foliar application on lowbush blueberries
• Seed treatment of field corn and seed corn for corn rootworm
• Seed treatment of soybean for bean leaf beetle, European chafer, soybean aphid and wireworm
• In-furrow application for leafy vegetables, for cabbage looper, beet armyworm, corn earworm and fall armyworm
• Soil drench and in-furrow application for Brassica vegetables, for dipteran leafminer, cabbage looper, diamondback moth, imported cabbageworm, thrips, beet armyworm, corn earworm, fall armyworm and yellowbanded armyworm

End of use delayed to April 11, 2022, for the control of certain insects.

Other risk reduction measures

As of April 11, 2021

• Application prohibited before or during flowering on the following crops:
  • Legumes
  • Fruiting vegetables grown outdoors
  • Berries — foliar application is still possible after flowering on woody berries provided that regeneration pruning is carried out after harvest
• Foliar application prohibited during flowering on sweet potatoes and potatoes
• Addition of warnings to minimize exposure of bees to dust produced during the planting of treated cereals and legumes

As of March 31, 2023

• Reduction of the maximum treatment rate for the following seeds:
  • Field corn
  • Seed corn
  • Soybean
• Reduction of the maximum rate for soil drench and in-furrow applications for the following crops:
  • Leafy vegetables
  • Brassica vegetables
• Limit to one application per season at the maximum application rate on fruiting vegetables for stink bug, tarnished plant bug and brown marmorated stink bug
• Limit of one single foliar application per season on the following crops:
  • Dry beans
  • Potatoes
  • Soybeans
  • Cranberries
  • Celeriac
  • Peppers, for pepper weevil
• Flood water must be held back for 30 days for cranberries that require flooding
• Updated buffer zones
• Recommendation of a vegetative filter strip

Users must follow the instructions on the updated labels.

Using a pesticide contrary with the label directions is a violation of the Pest Control Products Act.

Read the label

All pesticides registered in Canada have a Health Canada-approved label with a registration number. Read the pesticide label carefully, as it contains specific information on how to use it.

To find the most up-to-date label, use our online label search tool or search for "Health Canada pesticide labels" using your favourite search engine.