Australia and the US have different food regulatory systems. In Australia, the Food Standards Australia New Zealand (FSANZ) sets food standards. In the US, the Food and Drug Administration (FDA) sets standards. These bodies operate independently and sometimes reach different conclusions about what's safe.
In Australia, a food can be labelled "gluten-free" if gluten is not detectable using standard testing methods. In practice, this means less than 3 parts per million (ppm).
This informal threshold is based on the detection limit of common testing methods like ELISA (enzyme-linked immunosorbent assay). If you can't detect gluten, it's not there (at least not at measurable levels).
The US FDA defines gluten-free as containing less than 20 ppm of gluten. This is significantly higher than Australia's informal threshold.
The 20 ppm standard was chosen based on research suggesting that most people with coeliac disease can tolerate this amount without intestinal damage. The FDA reviewed studies and concluded that 20 ppm was the threshold below which most people would not experience symptoms.
The different thresholds reflect different regulatory philosophies. Australia aims for undetectable levels. The US aims for a tolerance threshold based on individual sensitivity. Both approaches are based on scientific evidence, but they emphasise different things.
The 3 ppm Australian threshold may be unnecessarily strict for some people. The 20 ppm US threshold may not be safe for sensitive individuals. The reality is that gluten sensitivity varies between people.
The biggest practical difference between Australia and the US concerns oats. Pure, uncontaminated oats contain no gluten. However, during cultivation and processing, oats can be contaminated by wheat or barley.
In the US, certified gluten-free oats are considered safe for a gluten-free diet. In Australia, oats are treated more cautiously because of contamination risk. Most Australian health professionals recommend avoiding oats unless specifically certified gluten-free by a Australian standards authority.
The difference in oat standards reflects a genuine scientific debate about avenin (a protein in oats that's similar to gluten) and cross-contamination. Some research suggests pure oats are safe. Other research suggests some people with coeliac disease react to oats even when uncontaminated. Both Australia and the US are being cautious in different ways.
A food might be made from gluten-free ingredients but become contaminated during manufacturing. If a facility processes wheat and gluten-free products on the same line or equipment, cross-contamination is possible.
Both Australia and the US have rules about manufacturing processes and labelling of "shared facility" foods. But the thresholds differ, so a product labelled safe in one country might not meet the other country's standard.
You might see products labelled "low gluten" (less than 20 ppm but more than 3 ppm). In the US, this product could not be labelled gluten-free. In Australia, "low gluten" labelling is less common because the standard is more strict.
If you have coeliac disease and are moving between Australia and the US, you should understand that gluten standards differ. A food labelled gluten-free in the US might not meet Australian standards and vice versa.
Gluten sensitivity varies between individuals. Some people with coeliac disease tolerate 20 ppm without symptoms. Others react to any detectable gluten. The safest approach is to know your own tolerance and to understand the standards in your country.
When reading food labels, look for:
In Australia, look for Australian standards. In the US, look for FDA compliance. If you're sensitive, be cautious with products near the threshold.
Visit RefDat Gluten Guide for ratings of 348 foods under both Australian and US standards.