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Consumer Product Safety

Proposed Maximum Residue Limit PMRL2013-45, Pyroxasulfone

Pest Management Regulatory Agency
3 July 2013
ISSN: 1925-0843 (PDF version)
Catalogue number: H113-24/2013-45E-PDF (PDF version)

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Under the authority of the Next link will take you to another Web site Pest Control Products Act, Health Canada's Pest Management Regulatory Agency (PMRA) has granted full registration to technical grade pyroxasulfone and the end-use product Pyroxasulfone 85 WG Herbicide for use in Canada on field corn. The specific uses approved in Canada are detailed on the product label of Pyroxasulfone 85 WG Herbicide, Pest Control Product Act Registration Number 30572.

The evaluation of these pyroxasulfone applications indicated that the end-use product has merit and value, and the human health and environmental risks associated with their proposed uses are acceptable. Details regarding these applications can be found in Proposed Registration Decision PRD2012-20, Pyroxasulfone, posted to the Health Canada website on 3 August 2012.

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 limits (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 addition, the PMRA is proposing to establish MRLs for pyroxasulfone on sweet corn and popcorn to permit the import and sale of food containing such residues. The PMRA has determined the quantity of residues that are likely to remain in or on the imported commodities when pyroxasulfone is used according to label directions in the exporting country, and that such residues will not be a concern to human health. Details regarding the proposed MRLs on imported commodities can also be found in PRD2012-20.

Consultation on the proposed MRLs for pyroxasulfone was conducted via PRD2012-20. Information regarding the proposed MRLs can be found in Sections 3.5 and 7.1. Supporting field trial residue data are provided in Appendix I, Table 6. The PMRA received no comments in response to this consultation.

To comply with Canada's international trade obligations, consultation on the proposed MRLs is also being conducted internationally by notifying the Next link will take you to another Web site World Trade Organization, as coordinated by the Next link will take you to another Web site Standards Council of Canada.

The proposed MRLs for pyroxasulfone are as follows.

Table 1 - Proposed Maximum Residue Limits for Pyroxasulfone
Common Name Residue Definition MRL (ppmTable 1 footnote 1) Food Commodity

Table 1 footnotes

Table 1 footnote 1

ppm = parts per million

Return to table 1 footnote 1 referrer

Pyroxasulfone 3-[(5-(difluoromethoxy)-l-methyl-3-(trifluoromethyl)pyrazol-4-ylmethylsulfonyl]- 4,5-dihydro-5,5-dimethyl-1,2-oxazole, and the metabolite 5-difluoromethoxy-1-methyl-3-trifluoromethyl-1H-pyrazole-4-carboxylic acid 0.015 Field corn, popcorn grain, and sweet corn kernels plus cob with husks removed
3-[(5-(difluoromethoxy)-l-methyl-3-(trifluoromethyl)pyrazol-4-ylmethylsulfonyl]-4,5-dihydro-5,5-dimethyl-1,2-oxazole 0.01 Eggs, fat, meat and meat by-products of cattle, goats, hogs, horses, poultry, and sheep
0.001 Milk

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 Product Act, both for pesticides or for food commodities.

International Situation and Trade Implications

Pyroxasulfone is a new active ingredient that is concurrently being registered in Canada and the United States. The MRLs proposed for pyroxasulfone in Canada are the same as corresponding tolerances to be promulgated in the United States, except for livestock commodities, in accordance with Table 2, for which differences in MRLs/tolerances may be due to different practices.

Once established, the American tolerances for pyroxasulfone will be listed inthe Next link will take you to another Web site Electronic Code of Federal Regulations, 40 CFR Part 180, by pesticide.

Currently, there are no Codex MRLsFootnote 1 listed for pyroxasulfone in or on any commodity on the Codex Alimentarius Next link will take you to another Web site Pesticide Residues in Food website.

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

Table 2 - Comparison of Canadian MRLs, American Tolerances and Codex MRLs (where different)
Food Commodity Canadian MRL
(ppm)
American Tolerance
(ppm)
Codex MRL
(ppm)
Field corn, popcorn grain, and sweet corn kernels plus cob with husks removed 0.015 0.015 Not established
Eggs, fat, meat and meat by-products of cattle, goats, hogs, horses, poultry, and sheep 0.01 Not established Not established
Milk 0.001 Not established Not established

Next Steps

The PMRA invites the public to submit written comments on the proposed MRLs for pyroxasulfone 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.

Footnotes

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