24 February 2010
HC Pub.: 100051
ISBN: 978-1-100-14402-3 (print)
ISBN: 978-1-100-14403-0 (PDF)
Catalogue number: H113-24/2010-12E (print)
Catalogue number: H113-24/2010-12E-PDF (PDF)

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Under the authority of the Pest Control Products Act (PCPA), Health Canada's Pest Management Regulatory Agency (PMRA) has re-evaluated the human health and environmental risks as well as the value of tefluthrin and is proposing continued registration of products containing tefluthrin for sale and use in Canada.

Tefluthrin is a synthetic pyrethroid insecticide used to control northern corn rootworm, western corn rootworm, black cutworm, wireworms and seedcorn maggot in field corn, seed corn and sweet corn.

The evaluation of available scientific information found that products containing tefluthrin have value in the food and crop industry and do not present unacceptable risks to human health or the environment. However, as a condition of the continued registration of tefluthrin, new risk reduction measures are proposed. Details regarding the re-evaluation can be found in the corresponding Proposed Re-evaluation Decision PRVD2010-01, Tefluthrin.

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. In the absence of a specified MRL, the 0.1 ppm general MRL applies in accordance with section B.15.002 of the Food and Drug Regulations.

The re-evaluation of the Canadian field trial data supporting the registration of tefluthrin indicated that the Agency has sufficient residue data on file to propose MRLs for use on corn.

Consultation on the proposed MRLs for tefluthrin is being conducted domestically via Proposed Re-evaluation Decision PRVD2010-01, Tefluthrin. Information regarding the proposed MRLs can be found in Section 8.1.1.2, with supporting field trial residue data and a discussion of the international situation and trade implications provided in Appendix VI. The PMRA invites the public to submit written comments on the proposed MRLs for tefluthrin in accordance with the guidance found in Proposed Re-evaluation Decision PRVD2010-01, Tefluthrin.

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 Standards Council of Canada.

The proposed MRLs for tefluthrin in Canada in or on food, to be added to the MRL for milk already legally established, is as follows.

Table 1  Proposed Maximum Residue Limits for Tefluthrin

Common Name	Residue Definition	MRL (ppm)	Food Commodities
Tefluthrin	2,3,5,6-tetrafluoro-4-methylbenzyl (Z)-(1RS)-cis-3-(2-chloro-3,3,3-trifluoroprop-1-enyl)- 2,2-dimethylcyclopropanecarboxylate, including the metabolite (Z)-3-(2-chloro-3,3,3-trifluroro-1-propenyl)-2,2- dimethylcyclopropanecarboxylic acid	0.06	Field corn, sweet corn kernels plus cob with husks removed

A complete list of all MRLs established in Canada can be found on the Maximum Residue Limits for Pesticides webpage in the Pesticides and Pest Management section of Health Canada's website.

International Situation and Trade Implications

The proposed Canadian MRLs for tefluthrin are the same as the corresponding tolerances established in the United States (tolerances listed in the  Electronic Code of Federal Regulations by pesticide). Currently, Codex¹ MRLs have not been established for tefluthrin on any commodity. A listing of established Codex MRLs is available on the  Pesticide Residues in Food website.