Proposed Maximum Residue Limit PMRL2017-25, Sulfentrazone

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This consultation is now closed.

Pest Management Regulatory Agency
6 September 2017
ISSN: 1925-0843 (PDF version)
Catalogue number: H113-24/2017-25E-PDF (PDF version)

Under the authority of the Pest Control Products Act, Health Canada’s Pest Management Regulatory Agency (PMRA) has concluded that the addition of new uses on potatoes to the product label of STZ Herbicide, containing technical grade sulfentrazone, is acceptable. The specific uses approved in Canada are detailed on the label of STZ Herbicide, Pest Control Products Act Registration Number 32621.

The evaluation of this sulfentrazone application indicated that the end-use product has value and the human health and environmental risks associated with the new uses are acceptable.

Before registering a pesticide for food use in Canada, the PMRA must determine the quantity of residues that are likely to 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. This quantity is then legally established as a maximum residue limit (MRL). An MRL applies to the identified raw agricultural food commodity as well as to any processed food product that contains it, except where separate MRLs are specified for the raw agricultural commodity and a processed product made from it.

Consultation on the proposed MRL for sulfentrazone is being conducted via this document (see Next Steps, the last section of this document). A summary of the field trial data used to support the proposed MRL can be found in Appendix I.

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.

The proposed MRL, to be added to the MRLs already established for sulfentrazone, is as follows.

Table 1    Proposed Maximum Residue Limit for Sulfentrazone
Common Name Residue Definition MRL (ppm)Table Note 1 Food Commodity
Sulfentrazone N-[2,4-dichloro-5-[4-(difluoromethyl)-4,5-dihydro-3-methyl-5-oxo-1H-1,2,4-triazol-1-yl]phenyl]methanesulfonamide, including the metabolites N-(2,4-dichloro-5-(4-(difluoromethyl)-4,5-dihydro-5-oxo-1H-1,2,4-triazol-1-yl)phenyl)methanesulfonamide, and N-(2,4-dichloro-5-(4-(difluoromethyl)-4,5-dihydro-3-hydroxymethyl-5-oxo-1H-1,2,4-triazol-1-yl)phenyl)methanesulfonamide 0.15 Tuberous and corm vegetables (crop subgroup 1C)
Table Note 1

ppm = parts per million

Return to table note 1 referrer

MRLs are proposed for each commodity included in the listed crop groupings in accordance with the Residue Chemistry Crop Groups webpage in the Pesticides and Pest Management section of the website.

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

The MRL proposed for sulfentrazone in Canada is the same as corresponding American tolerances as listed in the Electronic Code of Federal Regulations, 40 CFR Part 180, by pesticide. Currently, there are no Codex MRLsFootnote 1 listed for sulfentrazone in or on any commodity on the Codex Alimentarius Pesticide Residues in Food and Feed webpage.

Next Steps

The PMRA invites the public to submit written comments on the proposed MRL for sulfentrazone up to 75 days from the date of publication of this document. Please forward your comments to Publications. The PMRA will consider all comments received before 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

Residue data for sulfentrazone in potatoes were submitted to support this domestic use on the STZ Herbicide label. In addition, a processing study in treated potatoes was reviewed to determine the potential for concentration of residues of sulfentrazone into processed commodities.

Maximum Residue Limit

The recommendation for a maximum residue limit (MRL) for sulfentrazone was based upon the submitted 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 potatoes.

Table A1 Summary of Field Trial and Processing Data Used to Support the MRL

Table A1 Summary of Field Trial and Processing Data Used to Support the MRL
Commodity Application Method
Total Application Rate (mg a.i./L) / DurationTable Note 1
Post-treatment Interval (hours) Lowest Average Field Trial Residues(ppm) Highest Average Field Trial Residues(ppm) Experimental Processing Factor
Potatoes Pre-emergent Soil / 408-441 65-158 <0.15 <0.15 No quantifiable residues were observed at exaggerated rates
Table Note A1

g a.i./ha = grams of active ingredient per hectare

Return to table note 1 referrer

Following the review of all available data, the MRL as proposed in Table 1 is recommended to cover residues of sulfentrazone. Residues of sulfentrazone in these crop commodities at the proposed MRL will not pose an unacceptable risk to any segment of the population, including infants, children, adults and seniors.

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