The initial studies of oats and gluten-sensitive individuals produced mixed results with some indicating that oats did affect those with gluten sensitivity symptoms and others producing no effect.
The reason for the variation in the studies is that oats are often contaminated by other grains such as wheat, barley and rye. These grains are known to definitely have an effect on individuals with gluten allergies and therefore produce the same effects when contaminated oats are consumed in great quantities.
At the farm, producers often grow these other crops, use the same machinery to harvest, use the same storage bins and use the same transport. Gluten impregnates into the steel and even if the production machinery is thoroughly cleaned, contamination is still predicted.
For years, all oats were classified as unsafe for individuals with celiac disease or gluten intolerance issues. Recent studies have found that different varieties of oats have varying levels of toxicity. A 2008 study revealed that 85 of 109 sources of oats were contaminated by wheat, barley and rye at a level that would be deemed unsafe for gluten-sensitive individuals (greater than 20mg per kg).
GF Harvest in the USA, found that by dedicating their fields totally to Oats, carefully controlling the contaminated grains in the fields, using workers to walk through and extract those foreign plants and dedicating all the equipment on the farm to oats, they have been able to produce a product that can now be tested to < 3 ppm This reading in Australia is the lowest possible reading and in effect shows that the products are uncontaminated by the gluten found in wheat, rye and barley. However in Australia, according to the current labelling laws, ANY product that contains oats is unable to be labelled gluten free.