Proposed Maximum Residue Limit PMRL2020-37, Tetraconazole

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Pest Management Regulatory Agency
6 November 2020
ISSN: 1925-0843 (PDF version)
Catalogue number: H113-24/2020-37E-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 new uses on various commodities to the product labels of Mettle 210 ME Fungicide and Mettle 125 ME Fungicide, containing technical grade tetraconazole, is acceptable. The specific uses approved in Canada are detailed on the labels of Mettle 210 ME Fungicide and Mettle 125 ME Fungicide, Pest Control Products Act Registration Numbers 32042 and 30673, respectively.

The evaluation of this tetraconazole application indicated that the end-use products have value and the human health and environmental risks associated with the new uses 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 MRLs for tetraconazole is being conducted via this document (see Next steps). A summary of the field trial data used to support the proposed MRLs can be found in Appendix I.

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 Canada's Notification Authority and Enquiry Point.

The proposed MRLs, to replace or be added to the MRLs already established for tetraconazole, are as follows.

Table 1 Proposed maximum residue limits for tetraconazole
Common name Residue definition MRL
(ppm)Footnote 1
Food commodity
Tetraconazole 1-[2-(2,4-dichlorophenyl)-3-(1,1,2,2-
2.0 Liver of cattle, goats, horses and sheepFootnote 2
1.0 Barley bran
0.9 Rapeseeds (crop subgroup 20A) (revised)
0.5 Barley flour; milk fat; wheat germ
0.3 Barley; fat of cattle, goats, horses and sheepFootnote 3; fruiting vegetables (crop group 8-09)
0.15 Cucurbit vegetables (crop group 9); wheat bran
0.09 Dried shelled pea and bean (except soybean) (crop subgroup 6C)
0.08 Meat byproducts of cattle, goats, horses and sheep (except liver),Footnote 4 wheat flour
0.06 MilkFootnote 5
0.05 Wheat
0.03 Fat of poultry
0.02 Meat and meat byproducts of poultry
0.01 Eggs, field corn, popcorn grain

MRLs are proposed for each commodity included in the listed crop groupings in accordance with the Residue Chemistry Crop Groups webpage in the Pesticides and Pest Management 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. For livestock commodities, differences in MRLs can also be due to different livestock feed items and practices.

Table 2 compares the MRLs proposed for tetraconazole in Canada with corresponding American tolerances and Codex MRLsFootnote 1. American tolerances are listed in the Electronic Code of Federal Regulations, 40 CFR Part 180, by pesticide. Currently, there are no Codex MRLs listed for tetraconazole in or on any commodity on the Codex Alimentarius Pesticide Index webpage.

Table 2 Comparison of Canadian MRLs and American Tolerances (where different)
Food commodity Canadian MRL
American Tolerance
Codex MRL
Liver of cattle, goats, horses and sheep 2.0 1.5 Not established
Milk fat 0.5 0.75 Not established
Fat of cattle, goats, horses and sheep 0.3 0.15 Not established
Meat byproducts of cattle, goats, horses and sheep (except liver) 0.08 0.15 Not established
Fat of poultry 0.03 0.05 Not established
Meat byproducts of poultry 0.02 0.05 Not established
Meat of poultry 0.02 0.01 Not established
Eggs 0.01 0.02 Not established

Next steps

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

Appendix I

Summary of field trial data used to support the proposed maximum residue limits

Residue data for tetraconazole in various crops were submitted to support the domestic use of Mettle 210 ME Fungicide and Mettle 125 ME Fungicide.

Maximum residue limits

The recommendation for maximum residue limits (MRLs) for tetraconazole was based upon the submitted field trial data, and the guidance provided in the OECD MRL Calculator. Table A1 summarizes the residue data used to calculate the proposed MRLs for various crops.

Table A1 Summary of field trial and processing data used to support the MRLs
Commodity Application method/ Total application rate
(g a.i./ha)Footnote 1
Preharvest interval
Lowest average field trial residues
Highest average field trial residues
Experimental processing factor
Wheat Foliar/220–235 30–51 0.01 0.039 Wheat bran: 3.7×
Wheat flour: 2.0×
Wheat germ: 10.6×
Barley Foliar/217–236 28–51 <0.01 0.248 Barley branFootnote 2: 3.7×
Barley flourFootnote 2: 2.0×
Dry pea Foliar/219–228 13–18 <0.01 0.048 Not required
Dry bean Foliar/223–229 13–15 <0.01 0.070 Not required
Foliar/224–236 20–22 <0.012 0.870 Refined oil: 0.1×
Field corn Foliar/95–105 29–95 <0.01 <0.01 No quantifiable residues observed at exaggerated rates
Cucumber Foliar/217–223 0 <0.01 0.080 Not required
Cantaloupe Foliar/216–220 0.014 0.077 Not required
Summer squash Foliar/217–231 <0.01 0.047 Not required
Bell pepper Foliar/144–149 0 0.014 0.059 Not required
Non-bell pepper Foliar/147–148 0.040 0.110 Not required
Tomato Foliar/144–153 0.016 0.097 Paste: 0.3×
Puree: 0.2×
Juice: 0.1×

Based on the dietary burden and residue data, MRLs are also proposed in Table A2 to cover residues of tetraconazole in livestock commodities.

Table A2 Proposed MRLs in livestock commodities
Commodity Proposed MRLs
Liver of cattle, goats, horses and sheep 2.0
Milk fat 0.5
Fat of cattle, goats, horses and sheep 0.3
Meat byproducts of cattle, goats, horses and sheep (except liver) 0.08
Milk 0.06
Fat of poultry 0.03
Meat and meat byproducts of poultry 0.02
Eggs 0.01

Following the review of all available data, MRLs as proposed in Table 1 are recommended to cover residues of tetraconazole. Residues of tetraconazole in these crop and livestock commodities at the proposed MRLs will not pose an unacceptable risk to any segment of the population, including infants, children, adults and seniors.

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