Gluten-Free Labeling: the FDA 20 ppm Rule

"Gluten-free" is one of the few front-of-package claims with a precise legal definition in the US. Since 2014, a food labeled gluten-free must contain less than 20 parts per million (ppm) of gluten, under an FDA rule written with people with celiac disease in mind. This guide explains what the rule covers, what it doesn't, and how to read gluten-free labels with confidence.

Who the rule is for

Gluten is a group of proteins found in wheat, barley, rye, and crossbreeds of these grains, such as triticale. In people with celiac disease, an autoimmune condition, eating gluten damages the lining of the small intestine. According to the NIH's National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK), celiac disease affects about 1% of people worldwide and an estimated 2 million people in the US, and the only treatment is a strict, lifelong gluten-free diet. Other people avoid gluten because of non-celiac gluten sensitivity or a wheat allergy, which are different conditions.

Before the FDA rule, "gluten-free" had no federal definition, and products using the term could vary widely. A consistent standard was meant to make labels trustworthy for people who depend on them.

What the FDA rule says

The 20 ppm limit

The FDA published its gluten-free labeling rule in August 2013, codified at 21 CFR 101.91, and manufacturers had to comply by August 2014. Under the rule, a food may be labeled "gluten-free," "no gluten," "free of gluten," or "without gluten" only if it contains less than 20 ppm of gluten. The FDA chose this level because it's the lowest amount that could be reliably detected with validated scientific methods at the time, and because most people with celiac disease can tolerate foods with very small amounts of gluten, as reflected in the international Codex Alimentarius standard, which uses the same limit.

Which foods can qualify

A food can carry a gluten-free claim if it meets the 20 ppm limit and is either:

• Inherently gluten-free, such as rice, corn, fruits, vegetables, eggs, milk, or plain meat; or
• Made without gluten-containing grains as ingredients; or
• Made with an ingredient from a gluten-containing grain that has been processed to remove gluten, such as wheat starch, as long as the finished food is under 20 ppm.

In the last case, the food still has to declare wheat as an allergen under federal allergen labeling law. Under 21 CFR 101.91(b)(3), the label is required to mark the word "wheat" with an asterisk or similar symbol linked to this statement: "The wheat has been processed to allow this food to meet the Food and Drug Administration (FDA) requirements for gluten-free foods."

Oats

Oats don't naturally contain gluten, but they're often grown and processed alongside wheat, barley, and rye, so cross-contact is common. Oats and oat products can be labeled gluten-free only if the finished food is under 20 ppm. Some people with celiac disease also react to a protein in oats, so medical guidance on oats varies.

The 2020 rule for fermented and hydrolyzed foods

Standard tests for gluten don't work well on foods that have been fermented or hydrolyzed, such as yogurt, sauerkraut, vinegar, some sauces, and certain beers, because those processes break gluten into fragments the tests can miss. In August 2020, the FDA issued a final rule to address this. For these foods, manufacturers must keep records showing the food met gluten-free requirements before fermentation or hydrolysis, and must evaluate their process for any possible gluten cross-contact. Distilled foods like distilled vinegar are treated as gluten-free because distillation removes gluten.

Most beers and other alcoholic beverages are regulated by the Alcohol and Tobacco Tax and Trade Bureau (TTB), not the FDA, and follow TTB's own policies on gluten-related claims.

What the rule doesn't cover

• Labeling is voluntary. A food that is naturally gluten-free isn't required to say so, and many don't.
• There's no required symbol. Third-party certification logos are private programs, and some set stricter limits than the FDA's 20 ppm.
• Restaurants are expected to be consistent with the FDA definition when they use the term, but oversight is largely local, and kitchen cross-contact is a real risk.
• Meat, poultry, and some egg products are regulated by the USDA rather than the FDA, and the FDA rule doesn't directly apply to them.
• "Wheat-free" is not the same as gluten-free. A wheat-free product can still contain barley or rye.

Reading labels if you avoid gluten

• Trust the FDA-defined claim on packaged foods: it means under 20 ppm.
• Without a claim, read the ingredients. Watch for wheat (including spelt, durum, farro, and semolina), barley, rye, triticale, malt, malt extract, malt vinegar, and brewer's yeast.
• Check the allergen statement. Wheat must be declared under federal law, but barley and rye aren't major allergens and won't appear in a "Contains" statement.
• Treat "may contain wheat" statements seriously. They're voluntary and not standardized, but they signal possible cross-contact.

How to use this on myfoodfact.com

• Browse our list of products with no gluten grains listed. It's built from the ingredient and allergen information in each product's data, not from lab testing or the FDA "gluten-free" claim, so always check the package itself.
• Look up unfamiliar ingredients, such as xanthan gum, a common thickener in gluten-free baking, in our ingredient directory.
• Learn how wheat and the other major allergens are declared in our guide to the 9 major allergens.

The bottom line

In the US, "gluten-free" on a packaged food means less than 20 ppm of gluten under 21 CFR 101.91, and since 2020 fermented and hydrolyzed foods must meet that standard through records of their ingredients before processing. The claim is voluntary, so its absence doesn't mean a food contains gluten, and its presence doesn't cover cross-contact at restaurants. For people with celiac disease, the claim plus a careful read of the ingredients list is the most reliable approach.

This guide is for general information and is not medical advice. If you have or suspect celiac disease, talk with your doctor before removing gluten from your diet, since testing for celiac disease is most accurate while you are still eating gluten.