Thursday, May 20, 2021

Health Canada gives Imidacloprid a reprieve

The Pest Management Regulatory Agency has issued a long list of restrictions for Imidacloprid, a popular neonicitinoid pesticide.

It did not ban the product as had been feared when Health Canada issued its proposals in 2016 to deal with neonicitinoids.

Gaucho, Merit, Admire, Alias and Sombrero have been cleared for continued sale.

Health Canada said Wednesday that comments and “new data/information received” led to revisions of its occupational and environmental risk assessments and “resulted in changes to the proposed re-evaluation decision.”

Some products have been banned, including Bayer’s Merit Granular and Merit Solupack wettable powder, Adama’s Quali-Pro 0.5 Granular and Quali-Pro 75 WSP wettable powder, and SBM’s BioAdvanced granular grub control.

New rates have been set at reduced levels:

- seed treatment for field corn at 13 grams of active ingredient per 80,000 seeds;

  • seed treatment for sweet corn, to 67.2 grams per 100 kg of seed;
  • seed treatment for soybean, to 62.5 grams per 100 kg of seed;
  • seed treatment for lettuce, broccoli and cabbage, to treatment of seed for crops grown or started in greenhouses, with no direct seeding to fields permitted;
  • foliar application for soybean, down to one application per season maximum, at a maximum application rate of 24.4 grams per hectare, and
  • foliar application for potato, legumes other than soybeans, and tobacco, down to one application per season.

The new cuts to imidacloprid’s maximum application rates lead to outright cancellation for some previously-allowed uses, such as:

  • seed treatment for corn flea beetle on field corn and sweet corn;
  • seed treatment for direct field seeding of brassica vegetables such as broccoli and cabbage and leafy vegetables such as lettuce;
  • in-furrow application on brassica, leafy and root and tuber vegetables, including potato;
  • in-furrow application on tobacco;
  • field application of tray plug drench application on leafy vegetables;
  • foliar and granular application on turf;
  • foliar application on lowbush blueberry; and
  • soil drench application on brassica, leafy, and root and tuber vegetables, including potato (but not sugar beet), based on the usual row spacing for those crops against the revised maximum application rates.

Greenhouse uses, such as a soil drench or transplant tray plug drench, are still allowed as long as “measures are in place to prevent releases, effluent or runoff from greenhouses containing this product from entering lakes, streams, ponds, or other waters.” Greenhouses using imidacloprid in a closed recirculation or closed chemigation system will have to pass third-party audits.

Imidacloprid product labels must also be changed to require spray buffer zones, inform users of “potential toxic effects to sensitive biota” and make note of revised restrictions for use of treated seed, such as seed disposal instructions and a ban on broadcast seeding of treated seed, Health Canada said.

The final re-evaluation decision also calls for risk-reduction measures to protect workers and those who enter imidalcoprid-treated areas, including changes to personal protective equipment  and engineering controls for seed treatment uses.

It also called for restricted-entry intervals and/or spray drift precautions where not already included on labels, and “clarification that the use in greenhouses is not allowed for uses only registered for outdoor areas.”

All product label changes must be made within 24 months, Health Canada said. 

Companies holding the registrations for cancelled products may still sell those products for one year from the decision’s publication date, followed by a year of sale at retail, followed by a year of permitted use.

The one exception among cancelled uses is as a soil drench for control of European chafer on ginseng crops. Ginseng growers were “found to lack suitable alternatives,” Health Canada said, so that cancellation will be delayed for 24 months.