29 January 2010
HC Pub: 8364
ISBN: 978 1 100 13361 4 (Print Version)
ISBN: (978 1 100 13362 1) (PDF Version)
Catalogue number: H113 24/2010 3F (Print Version)
Catalogue number: H113 24/2010 3F PDF (PDF Version)

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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 early postemergence use on field corn to the product label of Converge Flexx Herbicide, containing technical grade isoxaflutole, is acceptable. The specific use approved in Canada is detailed on the label of Converge Flexx Herbicide, Pest Control Products Act Registration Number 29071.

The evaluation of this isoxaflutole application indicated that the end-use product has merit and value and that the human health and environmental risks associated with the new use are acceptable. Details regarding the registration can be found in the corresponding Evaluation Report that is available in the Pesticides and Pest Management section of Health Canada's website, under Public Registry, Pesticide Product Information Database.¹

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 revised MRL for isoxaflutole is being conducted via this document (see Next Steps).

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 Standards Council of Canada.

The proposed MRL for isoxaflutole in Canada in or on food, to replace the corresponding MRL already legally established, is as follows.

Table 1 Proposed Maximum Residue Limit for Isoxaflutole

Common Name	Residue Definition	MRL (ppm)	Food Commodity
Isoxaflutole	(5-cyclopropyl-4-isoxazoly)[2-(methylsulfonyl)- 4-(trifluoromethyl)phenyl] methanone, including the metabolite 1-(2-methylsulfonyl-4-trifluorometylphenyl)- 2-cyano-3-cyclopropylpropane2	0.02	Field corn*

^* The proposed MRL of 0.02 ppm for field corn is to replace the established MRL of 0.2 ppm on corn due to the removal of a metabolite from the existing residue definition.

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 MRL is the same as the corresponding tolerance established on "corn, field, grain" in the United States (tolerances listed in the  Electronic Code of Federal Regulations by pesticide). Currently, Codex Alimentarius³ MRLs have not been established for isoxaflutole on any commodity. A listing of all established Codex MRLs is available on the  Pesticide Residues in Food website.

Next Steps

The PMRA invites the public to submit written comments on the proposed MRL for isoxaflutole 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 for isoxaflutole and posting a corresponding Established Maximum Residue Limit (EMRL) document in the Pesticides and Pest Management section of Health Canada's website.