How to read a food allergy label: the nine allergens you must see

What law is behind the allergen label?

In the United States, packaged-food allergen labeling is governed by the Food Allergen Labeling and Consumer Protection Act (FALCPA), codified at 21 U.S.C. § 343(w). The law requires that the nine major allergens be declared in clear, recognizable language — not just as obscure ingredients. The U.S. Food and Drug Administration (FDA) enforces it.

What are the nine major allergens?

Federal law names nine foods that trigger most serious reactions:

Milk
Eggs
Fish
Crustacean shellfish (such as crab, lobster, shrimp)
Tree nuts (such as almonds, walnuts, cashews)
Peanuts
Wheat
Soybeans
Sesame (added in 2023)

Where must the allergen appear on the label?

Labels must show each allergen one of two ways:

In the ingredients list, in plain English. “Wheat” must appear as wheat, not only as a less familiar form.
In a separate “Contains” statement, grouped near the ingredients, listing the allergens by name.

Either mention satisfies the federal requirement; a product does not need both. In practice, many manufacturers print both, which makes a quick scan easier.

Why is “may contain” not the same as “contains”?

You will also see voluntary notes such as “may contain,” “made on shared equipment with,” or “produced in a facility that also processes.” These are not required by federal law and the FDA does not standardize their meaning. For someone with a serious allergy, treat them as a signal to verify with the manufacturer rather than as a guarantee of safety — the absence of a “Contains” line does not prove a trace is impossible.

This pairs with the other date and claim labels on the package; see Food date labels explained, The Drug Facts panel explained, and How to read the Nutrition Facts label.

Why is “gluten-free” its own regulated claim?

“Gluten-free” is defined by the FDA (generally under 20 parts per million of gluten), which is different from a mere “wheat-free” note that could still allow barley or rye. For a gluten-sensitive reader, look for the regulated “gluten-free” claim specifically.

What about foods outside the package?

The federal rule applies to packaged, labeled foods. Restaurants and some unpackaged items follow different — often state-level — requirements, and cross-contact controls vary. Ask the establishment directly when the label is not in front of you.

What is the bottom line on allergen labels?

Read the “Contains” statement first: it must name any of the nine major allergens in plain language. Other foods can still cause allergic reactions — the law mandates labeling only for these nine. Voluntary “may contain” notes are not regulated, so verify with the maker when the allergy is serious.

This article is general information about food labeling, not medical advice. Allergen management should follow guidance from a clinician or registered dietitian, and state rules for restaurants and unpackaged foods vary.

Frequently asked questions

What are the nine major food allergens in the U.S.?

Federal law names milk, eggs, fish, crustacean shellfish, tree nuts, peanuts, wheat, soybeans, and sesame. Together they account for most serious food-allergy reactions in the United States. The Food and Drug Administration oversees how they must appear on labels.

Where on the label must allergens appear?

In one of two places. The allergen shows up in the ingredients list in plain English (for example, 'wheat' rather than only 'semolina'), or a separate 'Contains' statement near the ingredients lists them by name. Either mention satisfies the requirement, and manufacturers often do both.

What does a 'may contain' or 'made on shared equipment' note mean?

Those are voluntary advisory statements, not required by federal law. They signal a possible trace from shared lines, but the FDA does not standardize them, so their meaning varies by company. For a serious allergy, treat them as a reason to contact the manufacturer or choose another product rather than assuming they are safe.

Does 'gluten-free' mean the same as 'wheat-free'?

No. 'Gluten-free' is a regulated claim the FDA defines (generally less than 20 parts per million of gluten), while 'wheat-free' only means no wheat — it can still contain barley or rye. Someone avoiding gluten should look for the regulated 'gluten-free' claim, not just a wheat-free note.

Are allergens listed for foods sold unpackaged or in restaurants?

Not in the same way. The federal labeling law applies to packaged, labeled foods; restaurants and some unpackaged items follow different, often state-level rules. Ask the establishment directly, and recognize that cross-contact controls vary by location.

Sources

Each source is a primary or official reference, checked before publication. Links open the original.

Food Allergen Labeling and Consumer Protection Act — 21 U.S.C. § 343(w), the misbranding provision that requires the major food allergens to be declared on packaged-food labels — law.cornell.edu/uscode/text/21/343

Food and Drug Administration — 'Food Allergies' and major-food-allergens labeling guidance, including the two permitted declaration formats and the treatment of voluntary advisory 'may contain' statements (fda.gov was unreachable in this environment, so it is cited by name without a link)

Food Allergy Safety, Treatment, Education, and Research (FASTER) Act of 2021, Pub. L. No. 117-13 — the statute that added sesame as the ninth major allergen, effective January 1, 2023 — govinfo.gov/content/pkg/PLAW-117publ13/html/PLAW-117publ13.htm