Proposed Maximum Residue Limit PMRL2020-12, MCPA

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Pest Management Regulatory Agency
23 July 2020
ISSN: 1925-0843 (PDF version)
Catalogue number: H113-24/2020-12-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 annual canarygrass to the product labels of Curtail M Herbicide and XRM-5171 Herbicide, containing technical grade MCPA and clopyralid, is acceptable. The specific uses approved in Canada are detailed on the labels of Curtail M Herbicide and XRM-5171 Herbicide, Pest Control Products Act Registration Numbers 30914 and 22764, respectively.

The evaluation of these MCPA applications indicated that the end-use products have 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 MRLs for MCPA is being conducted via this document (see Next Steps). MRL consultation for the other active ingredient, clopyralid, present in Curtail M Herbicide and XRM-5171 Herbicide, is being conducted under a separate action. 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 MRLs is also being conducted internationally by notifying the World Trade Organization, as coordinated by the Canada’s Notification Authority and Enquiry Point.

The proposed MRLs, to be added to the MRLs already established for MCPA, are as follows.

Table 1 Proposed maximum residue limit for MCPA
Common name Residue definition MRL (ppm)Table 1 Footnote 1 Food commodities
MCPA (4-chloro-2-methylphenoxy)acetic acid 0.04 Annual canarygrass bran
0.03 Annual canarygrass seeds
Table 1 Footnote 1

ppm = parts per million

Table 1 Return to footnote 1 referrer

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 are no American tolerances for MCPA on the petitioned commodities listed in the Electronic Code of Federal Regulations, 40 CFR, part 180, by pesticide, nor are there Codex MRLsFootnote 1 listed for MCPA in or on the petitioned commodities on the Codex Alimentarius Pesticide Index webpage.

Next steps

The PMRA invites the public to submit written comments on the proposed MRLs for MCPA 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 MRLs. Comments received will be addressed in a separate document linked to this PMRL. The established MRLs will be legally in effect as of the date that they are entered into the Maximum Residue Limit Database.

Appendix I

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

Previously reviewed residue data from field trials conducted in/on wheat and barley were reassessed in the framework of this petition. In addition, processing studies in treated wheat were also reassessed to determine the potential for concentration of residues of MCPA into processed commodities.

Maximum residue limit

The recommendation for maximum residue limits (MRLs) for MCPA was based upon the field trial data on file, and the guidance provided in the OECD MRL Calculator. Table A1 summarizes the residue data used to calculate the proposed MRLs for annual canarygrass.

Table A1 Summary of field trial data used to support the MRLs
Commodity Application method/ Total application rate
(g a.i./ha)Table A1 Footnote 1
Preharvest interval (days) Lowest average field trial residues
Highest average field trial residues
Experimental processing factor
Wheat grain Broadcast foliar/ 1600–2200 43–98 <0.01 0.025 Wheat bran: 1.5×
No concentration in other processed fractions
Barley grain Broadcast foliar/ 800–900 56–79 <0.01 <0.01 Barley bran: 1.5×Table A1 Footnote 2
Table A1 Footnote 1

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

Table A1 Return to footnote 1 referrer

Table A1 Footnote 2

Processing factor extended from wheat

Table A1 Return to footnote 2 referrer

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

Footnote 1

The Codex Alimentarius Commission is an international organization under the auspices of the United Nations that develops international food standards, including MRLs.

Return to footnote 1 referrer

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