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Grain Industry Worried By New Toxin Limits

Canada’s grain industry wants safer food, but it doubts pending regulations to restrict exposure to ochratoxin A (OTA), a suspected carcinogen in grains and other foods, will be effective.

In the meantime, those regulations threaten to add costs throughout the pipeline from farmer to food processor.

“There really needs to be a supply chain solution,” Gordon Harrison, president of the Canadian National Millers Association (CNMA) said in an interview following the Canada Grains Council’s 41st annual meeting in Winnipeg last month. “Because of the difficulty in managing it (OTA) whatever we do needs to be meaningful in terms of the health outcome and it’s got to be practically achievable.”


The grains council devoted half a day to the OTA issue, followed by a two-day workshop on mycotoxins.

OTA is caused by penicillium mould that sometimes develops in stored crops after harvest. It’s invisible to the naked eye and unlike vomitoxin (DON), there are no telltale signs such as fusarium-damaged kernels to identify it as it’s delivered to the elevator.

Besides cereal grains, OTA is also found in coffee, grapes, wine, raisins, beer and even pork fed OTA-infected grain.

“Most of these (foods) are consumed daily by the majority of the population,” Mark Feeley, acting chief of Health Canada’s Chemical Health Hazards Assessment Division told the grains council meeting April 20.

“Most people in the limited


number of studies that have been done in Canada had detectable levels of OTA in their blood.”


Health Canada is proposing the maximum limit for OTA in raw grains be five parts per billion, three in directly consumed grains and 0.5 in infant cereals.

That’s not much. One part per billion is equivalent to one second in 32 years and one part per trillion is similar to a one-inch slice of pepperoni on a pizza the size of Texas. Low tolerances make it difficult to get consistent test results.

“The (OTA) levels are so low generally a bigger sample results in a lower number,” said Lawrence Klusa, the Canadian Wheat Board’s quality control manager. “The problem is when you take a small sample you could hit a bad seed and then your results are skewed.”

OTA is not a grading factor and there are no quick elevator tests to prescreen grain as it enters the handling system.

“An acceptable finding on inward grain doesn’t necessarily translate into an acceptable finding on outbound finished product,” Harrison said.


The uncertainty puts millers and food processors at financial risk.

Health Canada’s proposed limits are based on animal experiments that reveal OTA causes cancer when consumed at certain levels, as well as kidney disease and birth defects.

Maximum limits for OTA in food are aimed at reducing Canadians’ exposure without affecting their consumption habits, Feeley said.

“As has been pointed out there is no definitive evidence to date to show that ochratoxin A is causing harmful effects in humans,” he said.

Cantox Health Sciences International of Mississauga, hired by the CNMA to review Health Canada’s assessment, concludes the risk isn’t as great as Health Canada believes.

Given the problems getting accurate tests results and uncertainty about whether the proposed maximum limits will improve food safety, some in the grain industry question the merit of setting OTA limits. At the same time they don’t want to be seen opposing safe food.

Carleton University Professor David Miller, an expert in mycotoxins, said the European Union has found ways to manage OTA and Canada can too. He said four things should be done right away:

Check the fungi causing OTA to see if it’s the same one as in 1990s when it was last assessed;

Research ways to prevent OTA;

Develop a Hazard Analysis Critical Control Point (HACCP) system to keep OTA out of the handling system;

Develop a more sensitive OTA testing, which would result in more consistent results.

Children are the most at risk from OTA because of their small body weight, Feeley said. That’s why the proposed maximum limit is so low for infant cereals.

Wheat alone accounts for 55 per cent of a child’s exposure jumping to 85 per cent when rice is included.

“The good news is the level of OTAs in foods in Canada are generally low and the majority would not exceed the proposed MLs (maximum levels),” he said.

Based on recent sampling, nine per cent of the infant cereals contained OTA levels that exceed the proposed maximum levels, Feely said. Fifteen per cent of oats, five per cent of the durum, 5.5 per cent of the barley, three per cent of the hard wheat, 1.5 per cent of breakfast cereals and six per cent of the raisins failed the proposed OTA limits.

“Only one in 274 pasta samples actually did not meet the proposed ML,” Feeley said.

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MORE RISK: Gordon Harrison, president of the Canadian National Millers Association says controlling ochratoxin A in raw grains and foods requires co-operation throughout the grain system, including the farmer.

About the author


Allan Dawson

Allan Dawson is a reporter with the Manitoba Co-operator based near Miami, Man. Covering agriculture since 1980, Dawson has spent most of his career with the Co-operator except for several years with Farmers’ Independent Weekly and before that a Morden-Winkler area radio station.



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