The Pest Management Regulatory Agency (PMRA) has updated its guidance on the pyrethroid insecticide, lambda-cyhalothrin. While the agency has reinstated certain feed uses, it has cancelled use on apples and peaches at the request of registrants Syngenta and Sharda-CropChem Limited.  

Here’s a shortened version of the background provided by PMRA. 

Lambda-cyhalothrin is a synthetic pyrethroid insecticide used to control many types of insect pests in various settings. It is used on greenhouse food crops, terrestrial food and feed crops, shelterbelts, turf lawns, livestock, buildings, and ornamental plants. It has been registered for use in Canada since 1996.

On 29 April 2021, Health Canada's Pest Management Regulatory Agency (PMRA) published the Re-evaluation Decision RVD2021-04, Lambda-cyhalothrin and its associated end-use products. As a result of the re-evaluation decision, several uses were cancelled due to human health concerns. 

Following the 2021 decision, Syngenta Canada Inc. and Adama Agricultural Solutions Canada Ltd., applied to re-instate the cancelled feed uses, based on new data and a proposal to reduce the number of times per season this pesticide could be used on turf. Additionally, Syngenta Canada and Sharda CropChem Limited Inc. requested to remove the uses of two other lambda-cyhalothrin products on apples and peaches.

After thoroughly reviewing all relevant data, including the consideration of vulnerable populations, Health Canada concluded that the reduced use frequency on turf and the removal of specific food uses eliminated the human health concerns. As a result, Health Canada has reinstated certain feed uses of the product. These changes are designed to ensure that lambda-cyhalothrin continues to meet the requirements for protection of human health, based on the best available science. Health Canada has issued a decision for each of the applications received from Syngenta Canada Inc. and Adama Agricultural Solutions Canada Ltd.

Outcome of the decisions:

Under the authority of the Pest Control Products Act, Health Canada is:

• Re-instating the following livestock feed uses
  • Canola/Flax - seed and meal
  • Field corn grain and milled by products
  • Popcorn grain
  • Sweet corn grain
  • Legume vegetables (including pulses) -seeds
  • Soybean seeds, hulls, meal
  • Cereals - grains and milled by-products

• Cancelling registration for use on apples and peaches

• Reducing the use pattern on turf from being applied four times per season to being applied two times per season.

The following feed uses have not been re-instated, in other words, remain cancelled:

• Canola forage
• Field corn forage/silage, stover
• Popcorn stover
• Sweet corn forage, stover
• Legume silage, vine, hay
• Soybean forage, hay, silage
• Cereal forage, hay and straw
• Grasses (alfalfa, timothy) hay and straw
• Aspirated grain fractions (corn, soybeans and cereals)
• Potato culls

Corresponding product labels (refer to Appendix A) have been updated.

As a result of these decisions, new lambda-cyhalothrin maximum residue limits (MRLs) are proposed for animal food commodities and MRLs for apples and peaches are proposed for revocation. For more information, refer to the maximum residue limits section of the PMRA information note.

Source:  Pest Management Regulatory Agency February 3, 2025 posting