Food labeling can definitely be confusing when it comes to determining if a food is gluten-free. If a food is labeled gluten-free it has to contain less than 20 ppm gluten to adhere to the FDA requirements.

Gluten-Free Labeling:

• The FDA requires foods that are labeled gluten-free to contain less than 20 ppm of gluten.
• Gluten-free labeling is voluntary. Food manufacturers are not required to indicate all sources of gluten on the label, or indicate gluten-free status.
• The FDA is not mandating the use of a specific gluten-free label, so gluten-free labeling can vary from product to product. ^1,2

Which foods can be labeled gluten-free?

• Foods that are naturally GF
• Foods that contain gluten grains i.e. wheat starch, but have had the gluten removed to below 20 ppm.
• Foods that do not contain more than 20 ppm of gluten

AND any unavoidable gluten in the food due to cross-contact or migration of gluten from packaging material must be less than 20 ppm gluten.^{1, 2}

Gluten-free certification is different from gluten-free labeling and is done by an independent third-party organization. They have to follow the same or stricter requirements than the FDA. They vary in requirements, but most do not require testing of every batch. There are several different certifiers available on the market.

In general, you should be safe eating products labeled gluten-free. In a study where 275 foods labeled gluten-free were tested, 1.1% of them were found to contain more than 20 ppm gluten, so 98.9% tested gluten-free. Among foods that were not labeled gluten-free but had no gluten ingredients, 19.4% contained more than 20 ppm gluten and 10.2% contained more than 100 ppm gluten.³

Take home message: It is relatively safe to consume store bought products labeled gluten-free, but those not labeled gluten-free have a significantly higher risk of containing gluten.

References:

1. US Food and Drug Administration (FDA). Questions & Answers: Gluten-Free Food Labeling Final Rule. FDA Website: https://www.fda.gov/food/food-labeling-nutrition/questions-and-answers-gluten-free-food-labeling-final-rule . Accessed on May 29, 2019.
2. National Celiac Association. Gluten-Free, Off to A Fresh Start. Presentation. May 4, 2018.
3. Sharma GM, Pereira M, Williams KM. Gluten detection in foods available in the United States - a market survey. Food Chem. 2015;15(169):120-126

Reviewed and updated October 14, 2022.