Proposed Maximum Residue Limit PMRL2022-04, Thifensulfuron-methyl

Pest Management Regulatory Agency
16 March 2022
ISSN: 1925-0843 (PDF version)
Catalogue number: H113-24/2022-4E-PDF (PDF version)

Table of Contents

• Purpose of consultation
• Dietary health assessment
• Proposed MRLs
• International situation and trade implications
• Next steps
• Appendix 1
• References

Purpose of consultation

A Maximum residue limit (MRL)^{Footnote 1} is being proposed for the pesticide thifensulfuron-methyl, as part of the following application for Canadian use, under submission number 2021-0080.

Under the authority of the Pest Control Products Act, Health Canada's Pest Management Regulatory Agency (PMRA) has approved the above application to add the new commodity of camelina (Gold of Pleasure) to the product label of Pinnacle SG Toss-N-Go Herbicide containing technical grade thifensulfuron-methyl, to control specific weeds that impede growth of camelina. The specific uses approved in Canada are detailed on this product label, Pest Control Products Act Registration Number 30741.

The evaluation of this application indicated that the end-use product containing thifensulfuron-methyl has value, and the human health and environmental risks associated with the new use are acceptable. Dietary risks from the consumption of the food listed in Table 1 were shown to be acceptable when thifensulfuron-methyl is used according to the supported label directions. Therefore, food containing residues resulting from this use is safe to eat, and an MRL is being proposed as a result of this assessment. A summary of the field trial data used to support the proposed MRL can be found in Appendix I.

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 human risk by comparing the estimated human dietary exposure to the acceptable dietary level.

Before registering a pesticide for food use 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 above). If estimated human exposure is less than or equal to the acceptable level (developed in Step 2 above), Health Canada concludes that consuming residues resulting from use according to approved label directions is not a health concern. 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 for thifensulfuron-methyl is being conducted via this document. Health Canada invites the public to submit written comments on the proposed MRL for thifensulfuron-methyl in accordance with the process outlined in the Next Steps section of this document.
To comply with Canada's international trade obligations, consultation on the proposed MRL is also being conducted internationally by notifying the World Trade Organization, as coordinated by the Canada's Notification Authority and Enquiry Point.

Proposed MRLs

The proposed MRL, to be added to the MRLs already established for thifensulfuron-methyl, is summarized in Table 1.

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 or for food commodities.

International situation and trade implications

Currently, there is no American tolerance for thifensulfuron-methyl in or on the petitioned commodity listed in the Electronic Code of Federal Regulations, 40 CFR Part 180, by pesticide, nor are there Codex MRLs^{Footnote 2} listed for thifensulfuron-methyl in or on any commodity on the Codex Alimentarius Pesticide Index webpage.

Next steps

Health Canada invites the public to submit written comments on the proposed MRL for thifensulfuron-methyl up to 75 days from the date of publication of this document. Please forward your comments 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 separate document linked to this PMRL. The established MRL will be legally in effect as of the date that it is entered into the Maximum Residue Limit Database.

Appendix I

Summary of field trial data used to support the proposed maximum residue limit

To support the use of Pinnacle SG Toss-N-Go Herbicide on camelina (Gold of Pleasure), previously reviewed residue data from field trials conducted in/on canola were reassessed in the framework of this petition. Previously reviewed data was also reassessed to determine the potential for concentration of residues of thifensulfuron-methyl into processed commodities.

Dietary risk assessment results

Acute dietary (food plus drinking water) intake estimates indicated that females 13 to 49 years of age are exposed to less than 1%of the acute reference dose, and therefore are not a health concern.
Chronic dietary (food plus drinking water) intake estimates indicated that the general population and all population subgroups are exposed to less than 3%of the acceptable daily intake, and therefore are not a health concern.

Maximum residue limit

The recommendation for the maximum residue limit (MRL) for thifensulfuron-methyl was based upon the field trial data, and the guidance provided in the OECD MRL Calculator. Table A1 summarizes the residue data used to calculate the proposed MRL for Gold of Pleasure seeds.

Following the review of all available data, the MRL as proposed in Table 1 is recommended to cover residues of thifensulfuron-methyl. Dietary risks from exposure to residues of thifensulfuron-methyl in this crop commodity at the proposed MRL were shown to be acceptable for the general population and all subpopulations, including infants, children, adults and seniors. Thus the food that contains residues as listed in Table 1 is considered safe to eat.

References

None.