Re-evaluation Decision RVD2018-38, Thiram and Its Associated End-use Products

Pest Management Regulatory Agency
14 December 2018
ISSN: 1925-0886 (PDF version)
Catalogue number: H113-9/2018-38E-PDF (PDF version)

Summary

Table of Contents

• Re-evaluation Decision
• Outcome of Science Evaluation
• Regulatory Decision for Thiram
• Risk Mitigation Measures
• Next Steps
• Other Information
• Appendix I Registered Thiram Products in Canada

Re-evaluation Decision

Under the authority of the Pest Control Products Act, all registered pesticides must be regularly re-evaluated by Health Canada’s Pest Management Regulatory Agency (PMRA) to ensure that they continue to meet current health and environmental safety standards and continue to have value. The re-evaluation considers data and information from pesticide manufacturers, published scientific reports and other regulatory agencies. Health Canada applies internationally accepted risk assessment methods as well as current risk management approaches and policies.

Thiram is a contact fungicide registered for use as seed treatment (cereals, oilseeds, vegetables and feed/forage), foliar application on tree fruits (apple, peach and plum), strawberry and celery (plant beds), root dip of sweet potato sprouts, and as an animal repellent to protect dormant outdoor ornamentals and young fruit trees. Currently registered products containing thiram are listed in Appendix I.

The regulatory approach for the re-evaluation of thiram was first presented in the Proposed Re-evaluation Decision PRVD2016-07, Thiram.¹ PRVD2016-07 proposed the cancellation of all registered uses and the revocation of all maximum residue limits (MRLs) as health and environmental risks were not found to be acceptable. Health Canada received comments relating to the health, environmental and value assessments. These comments are summarized in Appendix II of Re-evaluation Decision RVD2018-38, Thiram and Its Associated End-use Products along with the responses by Health Canada. These comments and new data/information resulted in revisions to the risk assessments (see Science Evaluation Update of RVD2018-38), and subsequently, in changes to the proposed regulatory decision as described in PRVD2016-07. A reference list of data used as the basis for the proposed re-evaluation decision is included in PRVD2016-07, and further data used in the re-evaluation decision is listed in RVD2018-38.

Re-evaluation Decision RVD2018-38 presents the final re-evaluation decision² for thiram, including the required risk mitigation measures to protect human health and the environment. All products containing thiram that are registered in Canada are subject to this re-evaluation decision.

Outcome of Science Evaluation

Following the consultation on the proposed re-evaluation decision, Health Canada revised the dietary, occupational and environmental risk assessments based on new data/information received. As a result, registration of animal repellent uses and seed treatment uses, except for seed treatment of grasses, dry bulb onion, and alfalfa grown for forage, are acceptable for continued registration with the implementation of new mitigation measures and label amendments. Mitigation includes cancellation of commercial seed treatment of some seed types; however, on-farm treatment of these seeds is permitted. Health risks have not been shown to be acceptable for all other uses when these products are used according to current label directions, or when additional mitigation measures are considered. The environmental risks associated with the use of thiram and associated end-use products are acceptable when thiram products are used according to the revised label directions.

Regulatory Decision for Thiram

Health Canada has completed the re-evaluation of thiram. Under the authority of the Pest Control Products Act, Health Canada has determined that continued registration of some uses of thiram is acceptable. An evaluation of available scientific information found that these uses of thiram meet current standards for protection of human health and the environment when used according to the revised label directions, which include new mitigation measures: animal repellent uses and seed treatment uses, except for the seed treatment of grasses, dry bulb onion, and alfalfa grown for forage. The following uses of thiram are cancelled since health risks have not been found to be acceptable: all foliar uses on apple, peach, plum, strawberry, celery; sweet potato (sprout root dip); and seed treatment in Canada of grasses, dry bulb onion, and alfalfa grown for forage, as well as importation of these treated seeds into Canada. Label amendments, as summarized below and listed in Appendix III of RVD2018-38, are required. No additional data are required.

Risk Mitigation Measures

Registered pesticide product labels include specific directions for use. Directions include risk mitigation measures to protect human health and the environment and must be followed by law. The key risk-reduction measures required, as a result of the re-evaluation of thiram, are summarized below. Refer to Appendix III of RVD2018-38 for details.

Human Health

• The following uses are acceptable with the implementation of mitigation measures:
  • Commercial-class ornamental animal repellent: Add Personal Protective Equipment (PPE) and limit the amount handled when applying by paint brush.
  • Domestic-class ornamental animal repellent: Remove paintbrush application.
  • Seeds treated in Canada and imported into Canada (except those that are cancelled and listed below) including on-farm treatment of wheat, barley, oats, canola, mustard, rapeseed, rye, triticale, and corn: add increased PPE and engineering controls.
• Cancellation of the following uses:
  • All foliar uses (apple, peach, plum, strawberry, celery)
  • Sweet potato (sprout root dip)
  • Seed treatment in Canada of grasses, dry bulb onion, and alfalfa grown for forage, and importation of these treated seeds into Canada
  • Commercial seed treatment of wheat, barley, oats, canola, mustard, rapeseed, rye, triticale, and corn
  • On-farm liquid hopperbox/seed drill treatment for all crops.
  • Revocation of all MRLs of thiram, including those established for imports. Consultation on the revocation of all thiram MRLs will be conducted via a Proposed Maximum Residue Limit (PMRL) document.

Environment

Precautionary label statements to protect birds and mammals from treated seeds.

Next Steps

To comply with this decision, the required mitigation measures must be implemented on all product labels sold by registrants no later than 24 months after the publication date of this decision document. In addition, products that are cancelled will be phased-out following the implementation timeline outlined below.

• One (1) year of sale by registrant from the publication date of this decision document, followed by;
• One (1) year of sale by retailer from the last date of sale by registrant, followed by;
• One (1) year of permitted use from the last date of sale by retailer.

Other Information

Any person may file a notice of objection³ regarding this decision on thiram within 60 days from the date of publication of RVD2018-38. For more information regarding the basis for objecting (which must be based on scientific grounds), please refer to the Pesticides section of Canada.ca or contact the PMRA’s Pest Management Information Service.

Appendix I  Registered Thiram Products in Canada