The Canadian Celiac Association is warning against gluten-free Cheerios products over concerns the cereal is not 100 per cent safe for people with celiac disease.

Five types of Cheerios labelled gluten-free — Original, Honey Nut, Multi-Grain, Apple Cinnamon and Chocolate — were launched in Canada this summer.

General Mills launched gluten-free Cheerios in the U.S. last summer, but was forced to issue a recall shortly afterward because it said wheat flour was inadvertently mixed in with the oat flour.

Oats are naturally gluten-free, but farmers who grow oats may rotate their crops with grains that have gluten — such as wheat, barley and rye — posing a chance of contamination during harvest and transport, the Cheerios website says.

Oats sifted

But the website also says oats used in gluten-free Cheerios are sifted to sort out barley, wheat and rye.

Samantha Maloney, former president of the Ottawa chapter of the Canadian Celiac Association, told CBC Radio's All In A Day that the General Mills process in making gluten-free cereal is flawed.

"There's a bit of a problem with the way they're cleaning [the oats]," she said.

"The unfortunate thing is wheat and barley are often the same size, colour and weight of oat seeds and kernels, so they'll sometimes get mixed in. If they break, they could also be mixed in with the oats, so that's creating some contamination there."

Maloney said it's better to use "pure oats" to make gluten-free foods — that is, oats that haven't been contaminated with wheat, barley and rye to begin with.

Hearing stories

"Many companies are doing it right and people are eating it safely. That was the impression with General Mills at first," she said. 

But now she said she's hearing stories of people with celiac disease getting sick after eating Cheerios labelled as gluten-free.

"I wouldn't risk it," Maloney said. "… People are getting quite upset, and from what I've seen on the [celiac association's] social media is that people are starting to get really frustrated, because under the labelling laws that came into effect in 2012, this really shouldn't be happening. Gluten-free is gluten-free. No ifs, ands or buts."

In a statement, General Mills Canada told CBC News it performs "extensive testing" of its gluten-free Cheerios products.

"We start by confirming that each and every batch of oats are gluten free," the statement said. "After milling gluten-free oats into flour, we perform further testing to ensure that every batch of flour is gluten-free. Finally, we perform tests on every batch of Cheerios, confirming that our final products meet and exceed Health Canada's standards."

Listen to the full interview here.