Proposed Maximum Residue Limit PMRL2017-13, Quizalofop-ethyl

Pest Management Regulator4y Agency
11 May 2017
ISSN: 1925-0843 (PDF version)
Catalogue number: H113-24/2017-13E-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 Saskatoon berries to the product label of Assure II Herbicide, containing technical grade quizalofop-p-ethyl, is acceptable. The specific uses approved in Canada are detailed on the label of Assure II Herbicide, Pest Control Products Act Registration Number 25462.

The evaluation of this quizalofop-p-ethyl 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.

Residues of the resolved isomer quizalofop-p-ethyl are covered by MRLs established for quizalofop-ethyl, the unresolved isomeric mixture. Consultation on the proposed MRL for oxyfluorfen is being conducted via this document (see Next Steps). A summary of the field trial data used to support the proposed MRLs 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 quizalofop-ethyl, is as follows.

Table 1 Proposed Maximum Residue Limits for Quizalofop-ethyl
Common Name Residue Definition MRL (ppm)Table 1 footnote 1 Food Commodity

Ethyl 2-[4-[(6-chloro-2-quinoxalinyl)oxy]phenoxy]propanoate, including the acid metabolites of (RS)2-[4-(6-chloroquinoxalin-2-yloxy)phenoxy]propanoic acid, all expressed as quizalofop-ethyl

0.05 Saskatoon berries (juneberries)
Table 1 footnote 1

ppm = parts per million


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

MRLs may vary from one country to another for a number of reasons, including differences in pesticide use patterns and the locations of the crop field trials used to generate residue chemistry data.

Table 2 compares the MRL proposed for quizalofop-ethyl in Canada with the corresponding American tolerance and Codex MRLFootnote 1.2. American tolerances are listed inthe Electronic Code of Federal Regulations, 40 CFR Part 180, by pesticide. Currently, there are no Codex MRLs listed for quizalofop-ethyl in or on any commodity on the Codex Alimentarius Pesticide Residues in Food and Feed website.

Table 2 - Comparison of Canadian MRL, American Tolerance and Codex MRL (where different)
Food Commodity Canadian MRL (ppm) American Tolerance (ppm) Codex MRL (ppm)
Saskatoon berries (juneberries) 0.05 Not established Not established

Next Steps

The PMRA invites the public to submit written comments on the proposed MRL for oxyfluorfen 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 quizalofop-p-ethyl in Saskatoon berries were submitted to support the domestic use of Assure II Herbicide on Saskatoon berries.

Maximum Residue Limits

The recommendation for maximum residue limits (MRL) for quizalofop-ethyl 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 for Saskatoon berries (juneberries).

Table A1 - Summary of Field Trial Data Used to Support the MRL
Commodity Application Method / Total Application Rate (g a.i./ha)Table 1 footnote 1.1 Preharvest Interval (days) Lowest Average Field Trial Residues (ppm) Highest Average Field Trial Residues(ppm)
Saskatoon berries Broadcast application directed to the ground/ 72-75 41-56 <0.05 <0.05
Table 2 footnote 1

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


Following the review of all available data, the MRL as proposed in Table 1 is recommended to cover residues of quizalofop-ethyl. Residues of quizalofop-ethyl in Saskatoon berries 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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