Proposed Maximum Residue Limit PMRL2025-02, Tebuconazole

Pest Management Regulatory Agency
28 January 2025
ISSN: 1925-0843 (PDF version)
Catalogue number: H113-24/2025-2E-PDF (PDF version)

Table of Contents

• Background
• Purpose of consultation
• Dietary health assessment
• Proposed MRL revocation
• International situation and trade implications
• How to get involved
• Appendix I Dietary risk assessment results
• References

Background

Regulatory amendments to a maximum residue limit (MRL)^{Footnote 1} are being proposed for tebuconazole as a result of the re-evaluation of tebuconazole in Canada.

Tebuconazole is a systemic fungicide registered for food uses as foliar application to asparagus, barley, oats, soybean and wheat, as well as seed treatment of barley, corn, rye, oats, triticale and wheat seeds. Currently, MRLs are established for 97 food commodities, which include both domestically grown crops and imported products, with levels ranging from 0.03 to 10 ppm. This includes specific MRLs for imported commodities, such as grapes. Residues for tebuconazole on food commodities are regulated under the established MRLs for 'Tebuconazole' in the Maximum Residue Limit Database.

Results of the re-evaluation of tebuconazole

Under the authority of the Pest Products Control Act, Health Canada's Pest Management Regulatory Agency (PMRA) granted continued registration of products containing tebuconazole for sale and use in Canada after the re-evaluation process, provided new risk mitigation measures are put in place. To reflect the conclusion of the re-evaluation decision for tebuconazole, an MRL action is being proposed as outlined below.

Purpose of consultation

The purpose of this Proposed Maximum Residue Limit (PMRL) document is to:

• revoke the MRL of 5.0 ppm for grapes. 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.

Dietary health assessment

In assessing the risk of a pesticide, Health Canada combines information on pesticide toxicity with information on the degree and duration of dietary exposure to the pesticide residue from food. The risk assessment process involves four distinct steps:

1. Identifying the toxicology hazards posed by the pesticide;
2. Determining the "acceptable dietary level" for Canadians (including all vulnerable populations), which is protective of adverse health effects;
3. Estimating human dietary exposure to the pesticide from all applicable sources (domestic and imported commodities); and
4. Characterizing health risk by comparing the estimated human dietary exposure to the acceptable dietary level.

Before making any decision on the continuation of a pesticide's registration in Canada, Health Canada must determine the quantity of residues that could remain in or on the food when the pesticide is used according to label directions and that such residues will not be a concern to human health (Steps 3 and 4). If estimated human exposure is less than or equal to the acceptable level (developed in Step 2), Health Canada concludes that consuming residues resulting from use according to approved label directions is not a health concern. The results of the dietary risk assessment can be found in Appendix I.

The proposed MRL is then subject to consultation to legally specify it as an MRL. An MRL applies to the identified raw agricultural food commodity as well as to any processed food product that contains it, except for certain instances where different MRLs are specified for the raw agricultural commodity and its processed product(s).

Consultation on the proposed MRL action is being conducted via this document. Health Canada invites the public to submit written comments on the proposed MRL action in accordance with the process outlined in the How to get involved Section of this document.

To comply with Canada's international trade obligations, consultation on the proposed MRL action is also being conducted internationally by notifying the World Trade Organization, as coordinated by the Canada's Notification Authority and Enquiry Point.

Proposed MRL revocation

As a result of the updated dietary risk assessment for tebuconazole, the MRL of 5.0 ppm for grapes is proposed for revocation, as summarized in Table 1. After revocation, residues of tebuconazole in/on 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.

MRLs established in Canada may be found using the Maximum Residue Limit Database on the Maximum Residue Limits for Pesticides webpage. The database allows users to search for established MRLs, regulated under the Pest Control Products Act, both for pesticides and for food commodities.

International situation and trade implications

Internationally, MRLs are used to facilitate trade of food commodities between countries. Canadian MRLs are established or amended based on a robust scientific risk assessment that demonstrates safety for people in Canada. To mitigate human health risks associated with grapes, residues in these food commodities are proposed to be regulated under subsection B.15.002(1) of the Food and Drug Regulations at the general MRL (GMRL) of 0.1 ppm. Table 2 compares the MRL proposed for revocation in Canada for tebuconazole with the corresponding tolerance in the United States (U.S.) and the Codex MRL.^{Footnote 2}

The U.S. tolerances are listed in the Electronic Code of Federal Regulations, 40 CFR Part 180. The term "tolerance" is used in the U.S. as another name for MRL. The Codex MRLs are listed by pesticide or commodity on the Codex Alimentarius Pesticide Index webpage.

How to get involved

Health Canada invites the public to submit written comments on the proposed MRL action up to 75 days from the date of publication of this document (by 13 April 2025). Please forward your comments to Publications. Health Canada will consider all comments received and a science-based approach will be applied in making a final decision on the proposed MRL. Comments received will be addressed in a response to comments document found in Pesticides and pest management consultations. The revocation will be legally in effect as of the date that the MRL is removed from the Maximum Residue Limit Database.

Appendix I Dietary risk assessment results

Tebuconazole

The dietary assessment for tebuconazole was published for consultation in PRVD2021-08. Based on the comments and additional information received from the consultation on the PRVD, the toxicology reference values (TRVs) for tebuconazole were further updated and the drinking water estimated environmental concentrations (EECs) were further refined by lowering the maximum yearly application rate from 1440 g a.i./ha per year, down to 136 g a.i./ha per year. Due to these revisions, the dietary risk assessment used to support PRVD2021-08 was updated for the re-evaluation decision (RVD2024-09).

When considering the updated TRVs, refined EECs reflecting the lower maximum yearly rate (136 g a.i./ha per year), and residues on grapes not exceeding 0.1 ppm, the refined dietary exposure and risks (from food and drinking water) were found to be acceptable for all subpopulations (maximum of 94% of the acute reference dose and 22% of the acceptable daily intake for the most exposed subpopulation of females 13–49).

Following the re-evaluation of tebuconazole, the revocation of the MRL listed in Table 1 is recommended. The updated dietary risk assessment for tebuconazole demonstrates that, with a reduced use pattern (including cancellation of all turf uses, limiting the cumulative application rate to a maximum of 136 g a.i./ha/year for all crops), and the revocation of the MRL for grapes, dietary risks meet Health Canada's requirements for protecting human health across all populations, including infants, children, adults, and seniors.

References

RVD2024-09, Tebuconazole and Its Associated End-use Products

PRVD2021-08, Tebuconazole and Its Associated End-use Products – Publication request page