Gluten-free labeling and 20 ppm.

What 21 CFR 101.91 covers

Section 101.91 is titled "Gluten-free labeling of food." It defines the terms, states what is misbranded, sets compliance and recordkeeping rules for fermented, hydrolyzed and distilled foods, and preempts different state rules. The eCFR version on this page is current through October 29, 2026, and its history runs 78 FR 47178 (August 5, 2013), amended at 85 FR 49260 (August 13, 2020).

Definitions: paragraph (a)

• (a)(1) Gluten-containing grain. Wheat (any species of the genus Triticum), rye (Secale) or barley (Hordeum), or their crossbred hybrids, such as triticale.
• (a)(2) Gluten. "The proteins that naturally occur in a gluten-containing grain and that may cause adverse health effects in persons with celiac disease (e.g., prolamins and glutelins)."
• (a)(3) The claim "gluten-free." The food does not contain (1) a gluten-containing grain ingredient such as spelt wheat, (2) an ingredient derived from such a grain that has not been processed to remove gluten, such as wheat flour, or (3) an ingredient derived from such a grain and processed to remove gluten, such as wheat starch, if its use results in 20 ppm or more gluten in the food; or the food inherently does not contain gluten. In both cases any unavoidable presence of gluten is below 20 ppm gluten, "i.e., below 20 mg gluten per kg of food."

What is misbranded: paragraph (b)

A food bearing "gluten-free" that fails (a)(3) (and, where they apply, the (c)(2) through (c)(4) record rules) is deemed misbranded. So is a food bearing "no gluten," "free of gluten" or "without gluten." There is also a wheat rule in (b)(3): a food that has the word "wheat" in its ingredient list or "Contains wheat" statement, as required by the allergen provisions, and also claims gluten-free is misbranded unless the word "wheat" is followed immediately by an asterisk that refers to a nearby statement reading "The wheat has been processed to allow this food to meet the Food and Drug Administration (FDA) requirements for gluten-free foods."

How compliance is assessed: paragraph (c)

When compliance is based on analyzing the food, FDA says it will use a scientifically valid method that can reliably detect and quantify 20 ppm gluten in a variety of food matrices, raw and cooked or baked. Where no such method exists because the food is fermented or hydrolyzed, the manufacturer must make and keep records showing adequate assurance that the food was gluten-free before fermentation or hydrolysis, that processing was evaluated for gluten cross-contact, and that measures were taken where cross-contact potential was found; the same applies when an ingredient is fermented or hydrolyzed. Those records must be kept for at least 2 years after the food is introduced into interstate commerce and provided to FDA on request during an inspection. For distilled foods, FDA says it will verify the absence of protein in the distilled component by methods that can detect protein or protein fragments.

Preemption: paragraph (d)

States and their political subdivisions may not establish or continue any requirement that is different from the section for the definition and use of "gluten-free" and the three alternative phrases.

Worked example

A lab finds 3 mg of gluten in a 0.25 kg sample. 3 / 0.25 = 12 mg per kg, or 12 ppm. That is below 20 ppm, so it is within the unavoidable-presence limit in (a)(3)(ii). If 5 mg were found in the same sample, 5 / 0.25 = 20 ppm, which is not below 20 and so does not meet (a)(3)(ii). The ppm comparison is only one half of the definition: a food made with wheat flour fails (a)(3)(i) regardless of a low lab number, and a food using wheat starch that has had gluten removed fails if its use results in 20 ppm or more in the food.

Limits of this page

The tool converts a mass ratio. It does not validate a test method, a sampling plan, or the cross-contact records in (c)(2) to (c)(4), and a below-20-ppm result does not by itself make a food "gluten-free." It is not medical advice about celiac disease and not a labeling determination.

Sources

Sources opened and read November 2, 2026.

• eCFR: 21 CFR 101.91, Gluten-free labeling of food (current through October 29, 2026) (read November 2, 2026)
• eCFR: 21 CFR part 101, Food labeling (read November 2, 2026)