Proposed Maximum Residue Limit PMRL2013-39, Hexazinone

Pest Management Regulatory Agency
25 June 2013
ISSN: 1925-0843 (PDF version)
Catalogue number: H113-24/2013-39E-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 established forage alfalfa to the product label of Velpar DF Herbicide, containing technical grade hexazinone, is acceptable. The specific uses approved in Canada are detailed on the label of Velpar DF Herbicide, Pest Control Products Act Registration Number 25225.

The evaluation of this hexazinone application indicated that the end-use product has merit and value, and the human health and environmental risks associated with the new uses 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.^{Footnote 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 MRLs for hexazinone is being conducted via this document (see Next Steps).

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 hexazinone in Canada in or on food are as follows.

Table 1 - Proposed Maximum Residue Limits for Hexazinone

Common Name	Residue Definition	MRL (Table 1 footnote 1)	Food Commodity
Table 1 footnotes Table 1 footnote 1 = parts per million Return to table 1 footnote ppm referrer
Hexazinone	3-cyclohexyl-6-(dimethylamino)-1-methyl-1,3,5-triazine-2,4-(1H,3H)-dione, including the metabolites 3-cyclohexyl-1-methyl-6-(methylamino)-1,3,5-triazine-2,4-(1H,3H)-dione and 3-(3-hydroxycyclohexyl)-1-methyl-6-(methylamino)-1,3,5-triazine-2,4-(1H,3H)-dione, expressed as hexazinone equivalents	0.09	Milk
	3-cyclohexyl-6-(dimethylamino)-1-methyl-1,3,5-triazine-2,4-(1H,3H)-dione, including the metabolite 3-cyclohexyl-1-methyl-6-(methylamino)-1,3,5-triazine-2,4-(1H,3H)-dione, expressed as hexazinone equivalents	0.04	Fat, meat and meat byproducts of cattle, goats, hogs, horses and sheep

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 pesticide(s) or for food commodity(ies).

International Situation and Trade Implications

MRLs may vary from one country to another for a number of reasons, including differences in pesticide use patterns. For livestock commodities, differences in MRLs may also be due to different livestock feed items and practices.

As per Table 2, the proposed MRLs for hexazinone in Canada differ from corresponding tolerances established in the United States (tolerances are listed in the  Electronic Code of Federal Regulations, 40 CFR Part 180, by pesticide). Currently, there are no Codex MRLs^{Footnote 2} listed for hexazinone in or on any commodity on the Codex Alimentarius  Pesticide Residues in Food webpage.

Table 2 - Comparison of Canadian MRLs, American Tolerances and Codex MRLs

Food Commodity	Canadian MRL (ppm)	American ToleranceTable 1 footnote (ppm)
Table 1 footnotes Table 1 footnote 1 The American residue definition for milk includes two additional metabolites not captured in the Canadian definition (Metabolite C and F), and the definition for all other livestock commodities includes one additional metabolite (Metabolite F). The chemical names of the additional metabolites are found in the Electronic Code of Federal Regulations under 40 CFR Part 180.396. Return to table 1 footnote referrer
Fat of cattle, goats, hogs, horses and sheep	0.04	0.1
Meat of cattle, goats, hogs, horses and sheep	0.04	0.5
Meat byproducts of cattle, goats, hogs, horses and sheep	0.04	4.0
Milk	0.09	11

Next Steps

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