Re-evaluation decision RVD2024-09, Tebuconazole and its associated end-use products

• Pest Management Regulatory Agency
• 20 November 2024
• ISSN: 1925-1025 (PDF version)
• Catalogue number: H113-28/2024-9E-PDF (PDF version)

Summary

Table of contents

• Re-evaluation decision for tebuconazole and associated end-use products
• Re-evaluation decision for tebuconazole
• Risk mitigation measures
• Implementation of the re-evaluation decision
• Next steps
• Other information
• Appendix I - Registered products containing Tebuconazole in Canada

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 meet current health and environmental standards and 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. More details, on the legislative framework, risk assessment and risk management approach, are provided under the Evaluation Approach Section of the full version of Re-evaluation decision RVD2024-09, Tebuconazole and its associated end-use products.

Tebuconazole is a systemic fungicide registered for foliar uses (including large field crops, asparagus, and turf), seed treatments, 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 decision.

Currently registered products containing tebuconazole can be found in the Pesticide Product Information Database and in Appendix I. The Proposed Re-evaluation Decision PRVD2021-08, Tebuconazole and Its Associated End-use Products^{Footnote 1} containing the evaluation of tebuconazole and proposed decision, underwent a 90 day consultation period ending on 21 October 2021. PRVD2021-08 proposed continued registration of tebuconazole and all associated end-use products provided new risk mitigation measures are put in place. The proposed mitigation measures included increased personal protective equipment and engineering controls, restricted-entry intervals for agricultural products, reduction of the total seasonal application rate for turf, precautionary environmental label statements and spray buffer zones.

Health Canada received comments (and information) relating to the health, environmental and value assessments. Commenters are listed in Appendix II of RVD2024-09. These comments are summarized in Appendix III of RVD2024-09 along with the responses by Health Canada. These comments and new data/information resulted in revisions to the human health and, environmental risk and value assessments (see Science evaluation update of RVD2024-09), and resulted in changes to the proposed re-evaluation decision described in PRVD2021-08.

A reference list of information used as the basis for the proposed re-evaluation decision is included in PRVD2021-08, and further information used in the re-evaluation decision (RVD2024-09) is listed in Appendix X of RVD2024-09. Therefore, the complete reference list of all information used in this final re-evaluation decision includes both the information set out in PRVD2021-08 and the information set out in Appendix X of RVD2024-09.

This document (RVD2024-09) presents the final decision^{Footnote 2} for the re-evaluation of tebuconazole, including the required amendments (risk mitigation measures) to protect human health and the environment, as well as label amendments required to bring labels to current standards. All products containing tebuconazole that are registered in Canada are subject to this re-evaluation decision. As discussed above, the exception to this decision are products containing tebuconazole registered for joinery wood use.

Re-evaluation decision for tebuconazole

Health Canada has completed the re-evaluation of tebuconazole. Under the authority of the Pest Control Products Act, Health Canada has completed all required evaluations and consultations and has determined that the registration of products containing tebuconazole is required to be amended, in accordance with paragraph 21(2)(a) of the Pest Control Products Act. An evaluation of available scientific information respecting the health and environmental risks and value of tebuconazole found that certain uses of tebuconazole products meet current standards for protection of human health and the environment and have acceptable value when used according to the amended conditions of registration which includes new mitigation measures. However, all turf uses of tebuconazole are cancelled as risks due to exposure from drinking water were not shown to be acceptable when used according to the current conditions of registration, or when additional mitigation is considered. Label amendments, as summarized below and listed in Appendix IX of RVD2024-09, 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 required 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 RVD2024-09 for details.

Human health

The following risk-reduction measures are required for continued registration of tebuconazole in Canada:

The following maximum residue limit action is required to address potential dietary food exposure and risks:

• The import maximum residue limit of 5 ppm for grape commodities will be revoked. After revocation, residues of tebuconazole on/in grapes will be regulated under subsection B.15.002(1) of the Food and Drug Regulations, which requires that residues not exceed 0.1 ppm. A proposed maximum residue limit document will be published to inform the public of this decision.

The following mitigation measures are required to address potential dietary risks due to exposure from drinking water:

• All turf uses are cancelled. As a result, the registration of Mirage Stressgard (Registration Number 32405) and Dedicate Stress (Registration Number 33236) is cancelled.
• For all other remaining crops, the total seasonal rate is limited to a maximum of 136 g a.i./ha/year, except for those crops where the yearly total rate is currently below 136 g a.i./ha.
• The number of foliar applications per year for asparagus, and short rotation intensive culture (poplar and willow) are reduced to 1 application at 126 g a.i./ha.
• The number of foliar applications per year for soybean are reduced to either 1 application at 136 g a.i./ha or 2 applications at 65 g a.i./ha at a minimum 10-day interval.

For consistency with other labels:

• Rotational plant-back interval of 120 days is required for food and feed crops, unless the current label directions are more restrictive.

To protect workers handling commercial-class products or entering treated sites following application of these products, the following risk reduction measures are required:

• Increased personal protective equipment for mechanically-pressurized handguns and handheld airblast/mistblowers.
• Limit the amount of product handled per day for handheld airblast/mistblowers.
• A restricted-entry intervals of 12 hours for agricultural sites.

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 (ECCC, 2013).

To protect workers treating seed and handling treated seed:

• For corn seed, closed mix/load and transfer systems during commercial treatment.
• For corn seed, respiratory protection for baggers/sewers/stackers and cleaners.
• For wheat, barley, oat, rye, and triticale seed, personal protective equipment for cleaners and when planting commercially treated or imported seed.
• Closed cab tractor for planting treated seed.

Environment

To protect the environment, the following risk-reduction measures are required for continued registration of tebuconazole in Canada:

• 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). See the Spray Buffer Zone Label Statements section for the complete spray buffer zone table and drift mitigation instructions (Appendix IX of RVD2024-09).

Implementation of the re-evaluation decision

Regulatory Directive DIR2018-01, Policy on Cancellations and Amendments Following Re-evaluation and Special Review provides information and general timelines regarding the implementation of post-market decisions, (for example, up to 24-month timeline for label amendments and up to 36-month phase-out timeline for cancelled registrations), and Information Note: update on implementation of post-market decisions provides additional information on phase-out measures for post-market decisions that include cancellations. The post-market decision considers potential health and environmental risks regarding the use of the pest control product, and its value, when establishing the implementation timelines.

The health and environmental considerations for the implementation timeline for this final decision are outlined below.

Health considerations

Risks to human health from exposure to a pesticide are estimated by comparing potential exposures with the most relevant endpoint from toxicology studies, with standard protection factors incorporated to further protect human health, including the most sensitive population. These factors provide an inherent level of protection from exposures that could result in adverse effects to human health. Furthermore, Health Canada applies additional protection factors if warranted by the hazard profile of the pesticide or by the quality and completeness of the underlying data. When potential risks of concern are identified in the human health exposure scenarios, it does not necessarily mean that exposure will result in adverse effects, but mitigation measures to reduce potential risks would be required.

Potential and relative health risks are considered acceptable during the general 2-year implementation period unless there is evidence from incident reports or other sources of real-world post-market surveillance data suggesting that there are adverse health effects occurring as a result of the use of the product(s) according to the currently approved label/use conditions. Taking into consideration these factors, the general 2-year implementation timeline for label amendments for tebuconazole is considered appropriate from a human health perspective. Therefore, the required label updates will be implemented within 24 months following the publication of the re-evaluation decision document.

Similarly, Health Canada has determined that the identified health risks from the use of tebuconazole on turf is not expected to be serious or imminent over a three-year phase-out period for cancelled products registered for use on turf.

Environmental considerations

Registered labels for products containing tebuconazole currently include all the precautionary statements that were determined to be required by the environmental assessment for the re-evaluation. Buffer zones were recalculated based on revisions to the registered use pattern, and, as certain uses/applications rates were reduced or cancelled, the revised spray buffer zones are smaller or within the same range as buffer zones currently on product labels. Therefore, environmental precautionary statements and mitigative measures on product labels will be protective during the general 2-year implementation timeline for label amendments for pest control products containing tebuconazole, and environmental risks are considered to be acceptable.

Similarly, Health Canada has determined that the identified environmental risks from the use of tebuconazole on turf is not expected to be serious or imminent over a three-year phase-out period for cancelled products registered for use on turf.

Taking into consideration these factors, the general 2-year implementation timeline for label amendments for pest control products containing tebuconazole is considered appropriate from a human health and environmental perspective.

Amendment and cancellation timeframes

Based on the above considerations, the required amendments (mitigation measures and label updates) for pest control products containing tebuconazole must be implemented within 24-months from the date of this decision document. In addition, certain registrations of pest control products containing tebuconazole are cancelled as of the date of this decision document with a 36-month phase-out period.

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

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.

To comply with this decision, products registered for turf uses are cancelled (as of the date of publication) pursuant to paragraph 21(2)(b) of the Pest Control Products Act. Where risks of concern are not considered imminent and serious, existing stocks of the cancelled products are phased out in Canada following a general timeline of three (3) years from the publication date of the decision and following a sequential timeline provided for each level of the supply chain (in other words, at registrant, retail/distribution, and user levels). Health Canada has determined that the identified risks from the use of tebuconazole on turf are not expected to be serious or imminent over the three-year phase-out period.

Therefore, continued possession, handling, storage, and use of existing stock in Canada of these products will be authorized under paragraph 21(5)(a) of the Pest Control Products Act during the phase-out period as per the schedule below:

• Authorized for sale (of existing stocks in Canada) by registrant one (1) year from the date of decision, followed by;
• Authorized for sale by retailer/distributor (if applicable) one (1) year from the last date of sale by registrant, followed by;
• Authorized for use one (1) year from the last date of sale by retailer/distributor.

During the phase-out period, importing or manufacturing of products containing tebuconazole for turf use in Canada is prohibited. In addition, registrants are required to continue to comply with sales and incident reporting obligations during the phase-out period.

Other information

Any person may file a notice of objection^{Footnote 3} regarding this decision on tebuconazole 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 and pest management Section of the Canada.ca website (Public Engagement Portal - Public Engagement Forms - Notice of Objection) or contact PMRA's Pest Management Information Service.

The relevant confidential test data on which the decision is based (as referenced in PRVD2021-08 and in Appendix X of RVD2024-09) are available for public inspection, upon application, in PMRA's Reading Room. For more information, please contact the Pest Management Information Service.

Appendix I Registered products containing tebuconazole in Canada