Proposed Maximum Residue Limit PMRL2020-25, Aluminum Phosphide

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Pest Management Regulatory Agency
18 August 2020
ISSN: 1925-0843 (PDF version)
Catalogue number: H113-24/2020-25E-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 a new use on oilseeds (crop group 20) (revised) to the product labels of Weevil-Cide Tablets and Weevil-Cide Pellets, containing technical grade aluminum phosphide, is acceptable. The specific uses approved in Canada are detailed on the labels of Weevil-Cide Tablets and Weevil-Cide Pellets, Pest Control Products Act Registration Numbers 29455 and 30013, respectively.

The evaluation of this aluminium phosphide application indicated that the end-use products have value and the human health and environmental risks associated with the new use 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 aluminum phosphide is being conducted via this document (see Next steps). A summary of the information 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 replace MRLs already established for phosphine (by-product of aluminum phosphide), is as follows.

Table 1 Proposed maximum residue limit for phosphine
Common name Residue definition MRL (ppm)Table 1 Footnote 1 Food commodity
Aluminum phosphide phosphine 0.1 Oilseeds (crop group 20) (revised)Table 1 Footnote 2
Table 1 Footnote 1

ppm = parts per million

Table 1 Return to footnote 1 referrer

Table 1 Footnote 2

The proposed MRL is intended to replace the current MRLs of 0.1 ppm for safflower seeds, sesame seeds and sunflower seeds.

Table 1 Return to footnote 2 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 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

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 aluminum phosphide in Canada with corresponding American tolerances and Codex MRLsFootnote 1. American tolerances are listed inthe Electronic Code of Federal Regulations, 40 CFR Part 180, by pesticide. A listing of established Codex MRLs is available on the Codex Alimentarius Pesticide Index webpage, by pesticide or commodity.

Table 2 Comparison of canadian MRL, American Tolerance and Codex MRL (where different)
Food commodity Canadian MRL (ppm) American Tolerance (ppm) Codex MRL
Oilseeds (crop group 20) (revised) 0.1 0.1 (undelinted cottonseed, safflower seeds sesame seed, sunflower seed) Not established

Next steps

The PMRA invites the public to submit written comments on the proposed MRL for aluminum phosphide 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 information used to support the proposed maximum residue limit

Journal articles on the adsorption/desorption of aluminum phosphide by various cereal grains and pulses and a foreign review were submitted to support the domestic use of aluminum phosphide on oilseeds.

Maximum residue limit

The recommendation for the maximum residue limit for aluminum phosphide was based upon the submitted articles, history of use and foreign review.


Following the review of all available information, an MRL as proposed in Table 1 is recommended to cover residues of aluminum phosphide. Residues of aluminum phosphide 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.

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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