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Food and Nutrition

Health Canada's Maximum Levels for Chemical Contaminants in Foods

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Setting Maximum Levels for Contaminants in Foods

Health Canada's Bureau of Chemical Safety, Food Directorate is responsible for the assessment of risk to human health from exposure to food-borne chemical contaminants. When a potential safety concern is identified, appropriate risk management measures must be taken to reduce the risk of adverse health effects from exposure to the chemical. One risk management measure is the development of maximum levels (MLs) for chemical contaminants in retail foods. Maximum levels are established by Health Canada and are enforceable by the Canadian Food Inspection Agency. Certain MLs appear as regulatory limits in the List of Contaminants and Other Adulterating Substances in Foods whereas others are found as MLs in the List of Maximum Levels for Various Chemical Contaminants in Foods.

Maximum levels are established in an effort to reduce exposure to a particular contaminant. Exposure is affected by the concentration of the chemical in food and the amount of the food consumed. Therefore, both the concentration and the amount of food normally consumed must be considered when developing an ML. As a result, MLs for a particular chemical may differ depending on the food.

The toxicity of the chemical in question must also be taken into account in the establishment of MLs for contaminants in food, because different chemicals affect human health in different ways. For example, a certain level of exposure to one food contaminant may not have an adverse impact on human health, whereas similar exposure to a different contaminant may be very harmful.

When establishing MLs for contaminants in food, the primary concern is human safety, although the availability, nutritional value, and importance of the food in the Canadian diet are also considered.

There are a limited number of retail foods for which maximum contaminant levels have been developed. There are several reasons for this. The finding of a chemical in food does not automatically lead to the conclusion that there is an unacceptable health risk to humans. Most chemicals are found in food at such low levels that they do not pose a safety concern and therefore the establishment of MLs is not required. Levels of chemicals in food are monitored through regular surveillance activities by Health Canada and the Canadian Food Inspection Agency. Surveillance data are used to help identify potential contamination issues and, when warranted, appropriate risk management strategies are developed.

Even if a safety concern is identified and risk management action is required, the establishment of an ML may not necessarily be considered the best approach to reducing the risk associated with the food-borne chemical. For example, the presence of a contaminant in a food may be the result of an incident that was temporally or geographically isolated and that could have been avoided. In this case, appropriate risk management may involve removal of the contaminated food from retail shelves and corrective action at the food manufacturer or farm level to ensure that such contamination does not occur again. Short-term monitoring to ensure that the corrective action was successful would be required but the establishment of an ML may not be considered necessary.

The absence of an ML for a particular chemical contaminant does not mean that it is exempt from the Food and Drugs Act and Food and Drug Regulations. Paragraphs 4(1)(a) and (d), Part I, of the Food and Drugs Act state, respectively, that no person shall sell an article of food that has in or on it any poisonous or harmful substance or is adulterated. If an elevated concentration of a chemical contaminant is found in a food for which no ML exists, Health Canada may conduct a human health risk assessment to determine if there is a potential safety concern and whether risk management measures are required.

Lists of Canadian Maximum Levels

Canadian maximum levels (MLs) are set out in two separate lists.  The List of Maximum Levels for Various Chemical Contaminants in Foods comprises MLs established by Health Canada for contaminants and adulterating substances in certain foods. The List of Contaminants and Other Adulterating Substances in Foods sets out regulatory MLs and prohibitions.

Maximum levels are established by Health Canada and are enforceable by the Canadian Food Inspection Agency.

1. List of Contaminants and Other Adulterating Substances in Foods

Incorporated by reference under Division 15 of the Food and Drug Regulations, this list sets out the regulatory MLs established by Health Canada for certain contaminants and other adulterating substances found in specific foods. It also includes regulatory prohibitions against the presence of certain substances in foods, with some exceptions. This List was first established on 4 May 2016, consolidating information from B.01.046 and B.01.047 of Division 1, and Table 1, Division 15 of the Food and Drug Regulations.

List of Contaminants and Other Adulterating Substances in Foods: Incorporated by reference under Division 15 of the Food and Drug Regulations.

2.  List of Maximum Levels for Various Chemical Contaminants in Foods

This list has a history of being developed and maintained on Health Canada's website outside of the Food and Drug Regulations. These MLs were housed on the Department's website so that, relative to MLs that were in the Regulations, they could be updated as needed with greater ease and efficiency based on emerging scientific information. Health Canada intends to systematically review and then add, as appropriate, these MLs to the List of Contaminants and Other Adulterating Substances in Foods, thereby working toward the consolidation of all Health Canada MLs into a single list of regulatory MLs and prohibitions. This consolidation will take place over time and will involve public and stakeholder consultation.

With respect to other types of chemicals, pesticides are regulated under the Pest Control Products Act and maximum residue limits for pesticide residues in or on domestic and imported food are established by Health Canada's Pest Management Regulatory Agency. The Veterinary Drug Directorate develops maximum residue limits for veterinary drugs that could be present in a food derived from a food-producing animal that has been treated with such a drug.

Table 1: Maximum levels for various chemical contaminants in specified foods sold in Canada
Contaminant Maximum LevelTable 1 footnote 1 Food

Table 1 footnotes

Table 1 footnote 1

mg/kg (milligrams per kilogram) is equivalent to g/g (micrograms per gram) and ppm (parts per million)
 
g/kg (micrograms per kilogram) is equivalent to ng/g (nanograms per gram) and ppb (parts per billion)
 
Maximum levels for shellfish toxins, glycoalkaloids, and histamines are sometimes expressed as mg/100 g or g/100 g
 
to convert an ML in mg/kg to mg/100 g:
divide the value by 10 (e.g. 200 mg/kg = 20 mg/100 g)
 
to convert an ML in mg/kg to g/100 g:
multiply the value by 100 (e.g. 0.8 mg/kg = 80 g/100 g)

Return to table 1 footnote 1 referrer

Amnesic Shellfish Poisoning toxin (ASP) (Domoic acid) 20 mg/kg In bivalve shellfish edible tissue
Deoxynivalenol (Vomitoxin) 2.0 mg/kg
(under review)
In uncleaned soft wheat for use in non-staple foods
1.0 mg/kg
(under review)
In uncleaned soft wheat for use in baby foods
Diarrhetic Shellfish Poisoning toxins (DSP)
(sum of okadaic acid and dinophysis toxins (DTX-1, DTX-2 and DTX-3))
1 mg/kg
(under review)
In bivalve shellfish digestive tissue
0.2 mg/kg
(under review)
In bivalve shellfish edible tissue
Ethyl carbamate 30 µg/kg In table wines
100 µg/kg In fortified wines
150 µg/kg In distilled spirits
400 µg/kg In fruit brandies and liqueurs
200 µg/kg In sake
Glycoalkaloids, total (sum of alpha-solanine and alpha-chaconine) 200 mg/kg In potato tubers (fresh weight)
Histamines 200 mg/kg In anchovies, fermented fish sauces and pastes
100 mg/kg In other fish and fish products
3-MCPD
(3-monochloropropane-1,2-diol)
1 mg/kg In Asian-style sauces such as soy, oyster, mushroom sauces, etc.
Melamine 0.5 mg/kg
(combined concentration of melamine and cyanuric acid)
(interim maximum level)
In infant formula and sole source nutrition products, including meal replacement products
2.5 mg/kg
(combined concentration of melamine and cyanuric acid)
(interim maximum level)
In food products containing milk and milk-derived ingredients, except infant formula and sole source nutrition products, including meal replacement products
Mercury 0.5 mg/kg In the edible portion of all retail fish, with six exceptions (see the 1 ppm maximum level below).
[See also advice on canned white/albacore tuna via the "Mercury webpage"]
1 mg/kg The edible portion of escolar, orange roughy, marlin, fresh and frozen tuna, shark, and swordfish
[See advice on these six types of fish via the "Mercury webpage"]
Patulin 50 µg/kg In apple juice, including the apple juice portion of any juice blends or drinks, and unfermented apple cider
PAHs
(polycyclic aromatic hydrocarbons)
3 µg/kg B(a)P Toxic Equivalents
B(a)P = benzo(a)pyrene
In olive-pomace oils (this is a unique type of oil, distinct from other olive oils such as virgin olive oil)
PCBs
(polychlorinated biphenyls)
(under review) Fish
Meat & Dairy Products
Eggs
Poultry
Paralytic Shellfish Poisoning toxins (PSP)(saxitoxin equivalents) 0.8 mg/kg In bivalve shellfish edible tissue
Pectenotoxins (PTX) (sum of PTX-1, PTX-2, PTX-3, PTX-4, PTX-6 and PTX-11) 1 mg/kg In bivalve shellfish digestive tissue
0.2 mg/kg In bivalve shellfish edible   tissue