PMRA released their final decision on the re-evaluation of mancozeb fungicides on November 19, 2020.
Originally, PMRA proposed the cancellation of all uses of mancozeb, except greenhouse tobacco, due to risks to human health and the environment that were not found to be acceptable. Health Canada received comments and information relating to the health, environmental and value assessments. These comments and new data/information resulted in revisions to the toxicology, dietary, occupational and environmental risk assessments, and resulted in changes to the proposed re-evaluation decision.
An evaluation of available scientific information found that the registrant supported uses of mancozeb products (ground and aerial foliar application to potatoes; ground foliar application on apples, onions, sugar beets, ginseng, field cucumbers, field tomatoes, grapes, pumpkin, squash, and melon (including cantaloupe but excluding watermelon and in-furrow application to onions) meet current standards for protection of human health and the environment and have value when used according to the revised conditions of registration which includes new mitigation measures.
In grapes, a single application at 2.25 kg a.i. (3 kg of a 75% a.i. formulation) will be allowed with a 7-day restricted entry interval (REI) for hand leafpulling, training and crop thinning and a 66-day pre-harvest interval. In addition, mancozeb products will not be applied by handheld equipment.
Growers may use mancozeb products under the current labels (rate, number of applications, REI) until December 2022. Products affected by these changes include: Dithane Rainshield, Gavel DF, Manzate Pro-Stick, Penncozeb 75 DF Raincoat and Ridomil Gold MZ and any other formulated products containing mancozeb.