Proposed Re-evaluation Decision PRVD2021-08, Tebuconazole and Its Associated End-use Products

• Pest Management Regulatory Agency
• 23 July 2021
• ISSN: 1925-0967 (PDF version)
• Catalogue number: H113-27/2021-8E-PDF (PDF version)

Table of contents

• Proposed re-evaluation decision for tebuconazole and associated end-use products
• Proposed re-evaluation decision for tebuconazole
• Risk mitigation measures
• International context
• Next steps

Proposed re-evaluation decision for tebuconazole 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. Health Canada applies internationally accepted risk assessment methods as well as current risk management approaches and policies.

Tebuconazole is a systemic fungicide registered for foliar uses (including large field crops, asparagus, and turf), seed treatment, and as a heavy-duty wood preservative. The joinery wood use was assessed separately (RVD2017-06; Re-evaluation Decision for Joinery Use of Tebuconazole) and is not included in the current re-evaluation. Currently registered products containing tebuconazole can be found in the Pesticide Label Search and in Appendix I of PRVD2021-08.

This document (Proposed Re-evaluation Decision PRVD2021-08, Tebuconazole and Its Associated End-use Products) presents the proposed re-evaluation decision for tebuconazole, including the proposed amendments (risk mitigation measures) to protect human health and the environment, as well as the science evaluation on which the proposed decision is based. All products containing tebuconazole that are registered in Canada are subject to this proposed re-evaluation decision. This document is subject to a 90-day public consultation period,^{Footnote 1} during which the public (including the pesticide manufacturers and stakeholders) may submit written comments and additional information to PMRA Publications. The final re-evaluation decision will be published after taking into consideration the comments and information received during the consultation period.

Proposed re-evaluation decision for tebuconazole

Under the authority of the Pest Control Products Act and based on an evaluation of available scientific information, Health Canada is proposing continued registration of tebuconazole and all associated end-use products registered for sale and use in Canada.

Tebuconazole is of value to agricultural producers and turfgrass managers, as it controls numerous economically important foliar, seed-borne, and soil-borne diseases, as well as several damaging turfgrass pathogens. In addition, tebuconazole is used as a non-metallic heavy-duty wood preservative to extend the service life of treated wood, and is also used in conjunction with other active ingredients that protect treated wood against termite damage.

Risks to human health and the environment were shown to be acceptable when tebuconazole is used according to the proposed conditions of registration, which include the mitigation measures identified below.

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 proposed label amendments, including any revised/updated label statements and/or mitigation measures as a result of the re-evaluation of tebuconazole, are summarized below. Refer to Appendix IX of PRVD2021-08 for details.

Human health

As a result of the re-evaluation of tebuconazole, the PMRA is proposing further risk-reduction measures in addition to those already identified on tebuconazole product labels. Additional revisions to the tebuconazole labels are proposed to meet the current labelling standards and for consistency.

To protect the general population from dietary exposure including through drinking water:

• For turf uses, reduce the maximum cumulative rate from 3.10 kg a.i./ha/year to 1.44 kg a.i./ha/year.
• In addition, for consistency among product labels, a rotational plant back interval of 120 days is proposed for food and feed crops, unless the current label directions are more restrictive.

To protect workers using agricultural and turf end-use products:

• For mixer/loaders and applicators, additional or updated personal protective equipment.
• For postapplication workers harvesting (seedling production) short-rotation intensive culture crops (poplar and willow), a restricted-entry interval (REI) of 1 day.
• An REI of 12 hours is proposed for all other crop activities.
• For golf course turf, a re-entry interval of "until sprays have dried" is proposed.

To protect workers treating seed, workers conducting clean-up and repair activities at seed treatment facilities, and workers handling and planting treated seed:

• For corn seed, closed mix/load and transfer systems during treatment.
• For wheat, barley, oat, rye, and triticale seed, personal protective equipment during handling and planting treated seed, and when performing clean-up and repair activities.
• Closed cab tractor for planting of commercially-treated seed.

To protect workers treating wood and handling treated wood:

• Personal protective equipment, as per the "Recommendations for Design and Operation of Wood Preservation Facilities, 2013 Technical Recommendations Document", which is enforced by Environment and Climate Change Canada (PMRA# 3079324).

Environment

To protect the environment, the following risk mitigation measures are proposed:

• For products registered for use on turf, precautionary label statements to inform users of the potential toxic effects of tebuconazole to foliar-dwelling arthropods (certain beneficial insects) and birds.
• Precautionary label statements to inform users of the potential toxicity of tebuconazole to non-target terrestrial plants and aquatic organisms.
• Precautionary label statements on all outdoor uses of tebuconazole, except seed treatments, regarding potential for runoff to adjacent aquatic habitats for sites with characteristics that may be conducive to runoff and when heavy rain is forecast.
• Standard label statements to protect the environment from potential discharge or runoff of tebuconazole from wood preservation facilities.
• Spray buffer zones for the protection of non-target terrestrial and aquatic habitats (1–15 metres).

International context

Tebuconazole is acceptable for use in other Organisation for Economic Co-operation and Development (OECD) member countries, including the United States, European Union and Australia. No decision by an OECD member country to prohibit all uses of tebuconazole for health or environmental reasons has been identified.

Next steps

Upon publication of PRVD2021-08, the public, including the registrants and stakeholders, are encouraged to submit additional information that could be used to refine risk assessments during the 90-day public consultation period.

All comments received during the 90-day public consultation period will be taken into consideration in preparation of the re-evaluation decision document,^{Footnote 2} which could result in revised risk mitigation measures. The re-evaluation decision document will include the final re-evaluation decision, the reasons for it and a summary of comments received on the proposed re-evaluation decision with Health Canada's responses.

Refer to Appendix I of PRVD2021-08 for details on specific products impacted by this proposed decision.