Re-evaluation Decision RVD2022-04, Isoxaflutole and Its Associated End-use Products

• Pest Management Regulatory Agency
• 7 April 2022
• ISSN: 1925-1025 (PDF version)
• Catalogue number: H113-28/2022-4E-PDF (PDF version)

Summary

Table of contents

• Re-evaluation decision for isoxaflutole and associated end-use products
• Re-evaluation decision for isoxaflutole
• Risk mitigation measures
• Next steps
• Other information
• Appendix I - Registered products containing isoxaflutole in Canada

Re-evaluation decision for isoxaflutole and associated end-use products

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

Isoxaflutole is a broad spectrum herbicide registered for use in field corn and soybeans in Eastern Canada and British Columbia and for use in seed corn in Eastern Canada only. Currently registered products containing isoxaflutole can be found in the Pesticide Label Search and in Appendix I. The Proposed Re-evaluation Decision PRVD2021-02, Isoxaflutole ^{Footnote 1} containing the evaluation of isoxaflutole and proposed decision, underwent a 90 day consultation period ending on 29 April 2021. PRVD2021-02 proposed continued registration of all uses of isoxaflutole and associated end-use products registered for sale and use in Canada.

Health Canada received comments (and information) relating to the health and value assessments. Commenters are listed in Appendix II of Re-evaluation Decision RVD2022-04, Isoxaflutole and Its Associated End-use Products. These comments are summarized in Appendix III of RVD2022-04 along with the responses by Health Canada. The assessment of comments resulted in the reassessment of the proposed value-related label improvements but did not result in any other revisions to the value assessment, and did not result in changes to the proposed re-evaluation decision as described in PRVD2021-02.

A reference list of information used as the basis for the proposed re-evaluation decision was included in PRVD2021-02. There was no further information used in the re-evaluation decision of this RVD. Therefore, the reference list of all information used in the proposed re-evaluation decision, set out in PRVD2021-02, represents the complete reference of information used in this final re-evaluation decision.

This document (Re-evaluation Decision RVD2022-04) presents the final re-evaluation decision^{Footnote 2} for the re-evaluation of isoxaflutole, including the required amendments (risk mitigation measures) to protect human health and the environment. All products containing isoxaflutole that are registered in Canada are subject to this re-evaluation decision.

Re-evaluation decision for isoxaflutole

Health Canada has completed the re-evaluation of isoxaflutole. Under the authority of the Pest Control Products Act, Health Canada has determined that continued registration of products containing isoxaflutole is acceptable. An evaluation of available scientific information found that uses of isoxaflutole products meet current standards for protection of human health and the environment and have acceptable value when used according to revised conditions of registration which includes new mitigation measures.

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 required amendments, including any revised/updated label statements and/or mitigation measures, as a result of the re-evaluation of isoxaflutole, are summarized below. Refer to Appendix IV of RVD2022-04 for details.

Human health

Label improvements to meet current standards

As a result of the re-evaluation of isoxaflutole, Health Canada is proposing additional revisions to the isoxaflutole labels to update label statements to current policies and language.

• To protect bystanders, a statement is required indicating to apply only when the potential for drift to areas of human habitation or areas of human activity such as houses, cottages, schools and recreational areas is minimal.

Risk mitigation

To protect workers entering treated sites, a restricted-entry interval (REI) of 12 hours is required.

Environment

Risk mitigation

To protect the environment, the following risk-reduction measures are required:

• Standard label statements to inform users of the potential toxic effects of isoxaflutole to aquatic organisms and terrestrial plants.
• Spray buffer zones for the protection of aquatic and terrestrial habitats.
• A leaching advisory statement.
• Precautionary label statements to reduce the potential for runoff of isoxaflutole to adjacent aquatic habitats for sites with characteristics that may be conducive to runoff and when heavy rain is forecast.

Next steps

To comply with this decision, the required amendments (mitigation measures and label updates) must be implemented on all product labels no later than 24 months after the publication date of this decision document. Accordingly, both registrants and retailers will have up to 24 months from the date of this decision document to transition to selling the product with the newly amended labels. Similarly, users will also have the same 24-month period from the date of this decision document to transition to using the newly amended labels, which will be available on the Public Registry.

Refer to Appendix I for details on specific products impacted by this decision.

Other information

Any person may file a notice of objection^{Footnote 3} regarding this decision on isoxaflutole and its associated end-use products within 60 days from the date of publication of this Re-evaluation Decision. For more information regarding the basis for objecting (which must be based on scientific grounds), please refer to the Pesticides section of the Canada.ca website (Request a Reconsideration of Decision) or contact the Pest Management Information Service.

The relevant confidential test data on which the decision is based (as referenced in PRVD2021-02) are available for public inspection, upon application, in the PMRA's Reading Room. For more information, please contact the PMRA's Pest Management Information Service.

Appendix I Registered products containing isoxaflutole in Canada

Table 1 Registered products containing isoxaflutole in Canada^{Table 1 Footnote 1}

Registration number	Marketing class	Registrant	Product name	Formulation type	Active ingredient (%, g/L)
26141	Technical Grade Active Ingredient	Bayer CropScience Inc.	Isoxaflutole Technical	Solid	98.0%
33596		BASF Canada Inc.	BASF Isoxaflutole Technical Herbicide
26142	Commercial	Bayer CropScience Inc.	Converge 75 WDG Herbicide	Wettable Granules	75.0%
27446			Converge Pro	Suspension	480 g/L
29071			Converge Flexx Herbicide		240 g/L
32553		BASF Canada Inc.	Balance Bean Herbicide		480 g/L
33249			Balance Bean MTZ		Isoxaflutole: 105 g/L; Metribuzin: 420 g/L