Canada is a major player in exports of cereals and oil seeds. Not only that but Canadian food safety is revered as one of the finest with lowest adulterated incidences known. Canadian regulators establish Maximum Residue Limits (MRLs) for commodities where pesticides are used on crops within Canada and for those imported from countries that use other pesticides unregistered in Canada. Canadian regulators are very conservative in the establishment of MRL’s crops, because human and environmental health is paramount. Some countries may even rely on decisions made by Health Canada when determining their internal MRLs. For Health Canada utilizes principles of sound science throughout the process and incorporate large margins of safety so the overall risk to human health is not jeopardized.
Canola has the luxury of protection from various pests through the use of a number of pesticides. One particular pesticide is quinclorac which has been used to control cleavers, a weed that downgrades the crop yield and may have the potential to affect the crushing process. North American MRLs were established at a level of 1.5 ppm (reported as total quinclorac). PRTox was approached by growers to have samples from their fields analyzed for quinclorac residue. A small representative sample of canola yields were analyzed for total quinclorac residues, where the pesticide had been applied. Using LC/MS/MS it was observed that residue levels averaged 4.7 ppb, approximately 300 times below the Canadian MRL. Our results are consistent with other findings shared with our office where a larger data set of canola samples was investigated. The sound science techniques employed in our investigation show that quinclorac residue levels are well below the Canadian and US MRL’s. The pesticide multiresidue analysis panel method used by enforcement agencies around the world have a level of quantitation for most pesticides at 10 ppb.