In Canada, and in other countries, as part of normal and long-standing agricultural practices, cereal grains are often grown in close proximity to other types of grain, oil seeds and pulses. In addition, these grains can be harvested, stored and transported using the same equipment and facilities. Therefore, it is extremely difficult to keep all traces of these different crops from getting mixed in with each other at low levels. This unintended presence is most commonly referred to as co-mingling, but is sometimes referred to as inadvertent or adventitious presence, or agricultural cross contamination.
In fact, co-mingling is generally expected in the context of current industry practices, and is recognized under the Canadian Grain Quality Standards as established by the Canadian Grain Commission. Standards of quality for cereal grains are set to ensure a dependable commodity for domestic and export markets. However, in some cases the crop being harvested can be co-mingled with low levels of a food allergen or a gluten source, such as soy, wheat, rye or barley.
There are processes in place which help to clean grains, oil seeds and pulses before they are further processed into flours or other ingredients. These processes generally rely on the physical properties of these crops, such as individual seed sizes and shapes, to enable sorting. These processes have been shown to reduce, but not completely eliminate, the levels of unintended presence of trace amounts of other types of grain, oil seeds or pulses in cereal grains.
Health Canada is currently consulting with other federal departments involved in the cereal grain supply chain to more fully understand the nature and extent of agricultural grain co-mingling and its significance for individuals with food allergies and/or gluten intolerance. As an interim measure, Health Canada has developed consumer guidance related to a number of food allergens that can be found in specific commodities.
Follow Health Canada's consumer guidance for Canadians with food allergies to help avoid risks:
Also, you can join Health Canada's Food Allergies e-Notice, a free service to stay on top of issued advice as well as regulatory and scientific developments in the area of food allergens and intolerances in Canada.