Proposed Maximum Residue Limit PMRL2015-56, Imazapic

Notice to the reader:

The online consultation is now closed.

Pest Management Regulatory Agency
13 November 2015
ISSN: 1925-0843 (PDF version)
Catalogue number: H113-24/2015-56E-PDF (PDF version)

Under the authority of the  Pest Control Products Act, Health Canada's Pest Management Regulatory Agency (PMRA) is proposing to establish maximum residue limit (MRLs) for Imazapic in or on dry soybeans and sugarcane cane to permit the import and sale of foods containing such residues.

Imazapic is an herbicide not currently registered for use in Canada.

The PMRA must determine the quantity of residues that are likely to remain in or on the imported food commodities when imazapic is used according to label directions in the exporting country, and that such residues will not be a concern to human health. This quantity is then legally established as an MRL on the corresponding imported commodity. 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 imazapic are being conducted via this document (see Next Steps, the last section of this document). 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  Canada's Notification Authority and Enquiry Point.

The proposed MRLs for imazapic are as follows.

Table 1 Proposed Maximum Residue Limits for Imazapic
Common Name Residue Definition MRL (ppm)Table 1 footnote 1 Food Commodity

Table 1 footnotes

Table 1 footnote 1

ppm = parts per million

Return to table 1 footnote 1 referrer

Imazapic 2-[4,5-dihydro-4-methyl-4-(1-methylethyl)-5-oxo-1H-imidazol-2-yl]-5-methyl-3-pyridinecarboxylic acid 0.5 Dry soybeans
0.01 Sugarcane cane

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

Table 2 compares the MRLs proposed for imazapic in Canada with corresponding American tolerances and Codex MRLs.Footnote 1 American tolerances are listed inthe  Electronic Code of Federal Regulations, 40 CFR Part 180, by pesticide. A listing of established Codex MRLs is available on the Codex Alimentarius  Pesticide Residues in Food website, by pesticide or commodity.

Table 2 - Comparison of Canadian MRLs, American Tolerances and Codex MRLs (where different)
Food Commodity Canadian MRL (ppm) American Tolerance
Codex MRL
Dry soybeans 0.5 0.4 Not Established
Sugarcane cane 0.01 0.03 0.01

Next Steps

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


Summary of Field Trial Data Used to Support the Proposed Maximum Residue Limits

Residue data for imazapic in soybeans and sugarcane were submitted to support the maximum residue limit on imported soybeans and sugarcane. In addition, processing studies in treated soybeans and sugarcane were reviewed to determine the potential for concentration of residues of imazapic into processed commodities.

Maximum Residue Limit

The recommendation for maximum residue limits (MRLs) for imazapic was based upon the residues observed in crop commodities treated according to label directions in the exporting country, and the guidance provided in the  OECD MRL Calculator. Table A1 summarizes the residue data used to calculate the proposed MRLs for imported soybeans and sugarcane canes.

Table A1 - Summary of Field Trial and Processing Data Used to Support MRL
Commodity Application Method/ Total Application Rate
(g ai/ha)Table 2 footnote 1
Preharvest Interval (days) Minimum Residues
Maximum Residues
Experimental Processing Factor

Table 2 footnotes

Table 2 footnote 1

g ai/ha = grams of active ingredient per hectare

Return to table 2 footnote 1 referrer

Table 2 footnote 2

Residues of imazapic were not quantifiable in sugarcane stalks following treatment at exaggerated rates.

Return to table 2 footnote 2 referrer


Foliar broadcast/

60 <0.01 0.25 Oil: <0.13-fold
Flaked soybeans: 0.5-fold
Sugarcane stalks Pre-plant incorporated/ 245 150-365 <0.01 <0.01 Not applicableTable 2 footnote 2

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

Report a problem or mistake on this page
Please select all that apply:

Thank you for your help!

You will not receive a reply. For enquiries, contact us.

Date modified: