Questions and Answers on Maximum Residue Limits

On this page:

• What is a Maximum Residue Limit (MRL)? How is it determined?
• What is the General MRL? Why is it set at 0.1 parts per million (ppm)?
• Why is Health Canada proposing to eliminate the General Maximum Residue Limit of 0.1 ppm for pesticide residues on food?
• Is this approach consistent with the United States (U.S.), or other countries?
• How will Canadians benefit from this proposal?
• How will the re-evaluation of Canadian-registered pesticides affect this proposal?
• Why is Health Canada accepting tolerances that have been established in the U.S.?
• What is a Codex MRL?
• How will the PMRA deal with foods imported from other nations than the United States?
• Why has Health Canada released this proposal as a consultation paper?
• How long will the public consultation be?

What is a Maximum Residue Limit (MRL)? How is it determined?

A maximum residue limit (MRL) is the maximum concentration of a pesticide that may remain in or on a food at the farm gate when the pesticide is used according to registered label directions.

MRLs apply to residues on both food produced in Canada and food imported into Canada from other countries. These MRLs are currently established under the Food and Drug Regulations (FDR) of the Food and Drugs Act (FDA), only if Health Canada's Pest Management Regulatory Agency has determined that the consumption of the pesticide residues that could remain on the food as it is eaten will not pose an unacceptable health risk. Actual residues in food as it is eaten are usually much lower than the MRL.

What is the General MRL? Why is it set at 0.1 ppm?

The General MRL applies to foods that contain residues of agricultural chemicals (including pesticides) unless a specific MRL has been established. Regulation B.15.002(1) of the FDR establishes 0.1 ppm as the "General Maximum Residue Limit". This regulation states that a food is adulterated if it contains residues of a pesticide at a level greater than 0.1 ppm unless the residue conforms to a specific MRL that has been established. The FDA prohibits the sale of adulterated food.

The level of 0.1 ppm was chosen for several reasons. A key reason was that in the late 1970s, when the General MRL was set, the analytical methodologies then available were generally not sufficiently sensitive to detect most pesticides at levels below 0.05 ppm. Advances in analytical capabilities have now improved to such an extent that residues in a general food monitoring and surveillance program can now be detected at or below 0.01 ppm levels.

Why is Health Canada proposing to eliminate the General Maximum Residue Limit of 0.1 ppm for pesticide residues on food?

This initiative is part of Health Canada's ongoing efforts to modernize pesticide regulation in Canada, including risk reduction as required by the Pest Control Products Act.

The intent of the General MRL was to prohibit foods with higher than allowable levels of pesticides, but in practice, some of the consequences of the General MRL are that:

• Foods can enter Canada with residues of pesticides for which no request to establish an MRL had been made.
• Foods can enter Canada with residues of pesticides for which Canada has no information by which to determine if the residues pose risk to health.

Is this approach consistent with the United States, or other countries?

Yes, this is equivalent to the approaches of the United States. Most countries either do not allow any measurable residues unless specific MRLs are set, or they set very low default MRLs.

How will Canadians benefit from this proposal?

The proposal will maintain - and improve - the safety of the Canadian food supply. Setting pesticide/food-specific MRLs below the current 0.1 ppm level will lower allowable residues overall and thus reduce potential exposure to pesticides from food.

How will the re-evaluation of Canadian-registered pesticides affect this proposal?

In both Canada and the U.S., a number of pesticides are currently undergoing or are scheduled for re-evaluation over the next few years. Changes to Canadian MRLs may be necessary as a result of these re-evaluations, and will be implemented accordingly.

Why is Health Canada accepting tolerances that have been established in the U.S.?

The term tolerance is used in the United States to describe pesticide residue limits that Canada calls Maximum Residue Limits.

Health Canada has worked closely with the U.S. Environmental Protection Agency (EPA) for a number of years, and the two agencies have similar policies and standards that guide the establishment of tolerances and MRLs.

Based on its experience working with the U.S. EPA, we are confident that U.S. tolerances adequately reflect Canadian standards, and that relying on U.S. tolerances that are at or below 0.1 ppm will maintain or improve the safety of the Canadian food supply.

Much of the food that is imported into Canada either comes from U.S. sources or is also imported into the U.S. This proposal will adopt U.S tolerances for foods imported to Canada and the U.S. from other countries.

What is a Codex MRL?

The Codex maximum limit for pesticide residues (Codex MRL) is the maximum concentration of a pesticide residue (expressed as mg/kg), recommended by the Codex Alimentarius Commission to be permitted in or on food commodities and animal feeds. The Codex Alimentarius Commission was established by the Food and Agriculture Organization of the United Nations in 1961. Codex standards are considered reference standards for foods in international trade.

How will the PMRA deal with foods imported from other nations than the United States?

As noted above, much of the food that is imported into Canada from countries other than the U.S. is also imported into the U.S. These foods will therefore be covered by the adopted U.S. tolerances. However, we will also consider Codex MRLs at or below 0.1 ppm. If the Codex MRL of interest is greater than 0.1 ppm, those who are interested in having such an MRL established in Canada are invited to contact Health Canada for discussions on a case-by-case basis.

Why has Health Canada released this proposal as a consultation paper?

Previously, Health Canada released a consultation paper on the revocation of the default MRL. Considerable input and information was received; as a result, it was determined that a second consultation was warranted. This paper contains a more detailed proposal than the earlier paper, as well as responses to comments from interested groups on the initial proposal. Following the current consultation, we intend to propose an amendment to the Food and Drug Regulations, which currently provides the General MRL. When the amendment to the Food and Drug Regulations is published in Canada Gazette, Part 1, there will be another opportunity for comments.

How long will the public consultation be?

The 90-day comment period began June 23, 2006, and will end September 22, 2006. All written comments submitted during this time frame will be taken into consideration before drafting a proposed amendment to the Food and Drug Regulations.