Allergen

An allergen is a substance that causes an allergic reaction in sensitive individuals. US law requires nine major allergens to be declared on packaged food; the European Union requires fourteen. This page sets out both sets, how each must appear on a label, and the rules governing precautionary statements and cross-contact.

What is a food allergen and why does it matter?

A food allergen is a protein — or, less commonly, another component — in a food that the immune system of a sensitive individual incorrectly identifies as harmful. Upon exposure, the immune system mounts a response that can range from mild symptoms such as hives and nasal congestion to severe, life-threatening anaphylaxis. An estimated 33 million Americans live with food allergies, and reactions account for approximately 200,000 emergency department visits annually in the United States. For operators in food service and manufacturing, accurate allergen disclosure is both a regulatory obligation and a direct consumer safety measure. Incomplete or inaccurate allergen information on a label or menu is among the leading causes of preventable allergic reactions. Regulatory bodies in major markets — including the United States Food and Drug Administration (FDA) and the European Food Safety Authority (EFSA) — have established mandatory allergen declaration requirements to address this risk.

What are the FDA Big 9 allergens under FALCPA and the FASTER Act?

The Food Allergen Labeling and Consumer Protection Act of 2004 (FALCPA) established the original eight major food allergens that must be declared on labels of packaged foods regulated by the FDA: milk, eggs, fish, crustacean shellfish, tree nuts, peanuts, wheat, and soybeans. These eight allergens were estimated to account for 90 percent of serious allergic reactions in the United States. FALCPA applies to all packaged foods subject to the Federal Food, Drug, and Cosmetic Act (FD&C Act), with limited exemptions for raw agricultural commodities, certain highly refined oils, and foods regulated exclusively by the USDA. The allergen declaration must identify the specific type of nut, fish, or shellfish — for example, "almond," "salmon," or "shrimp" — rather than a generic category name alone. These requirements are codified at 21 CFR 101.4, which governs the declaration of ingredients on food labels.

In 2023, sesame became the ninth major food allergen recognized under United States law. The Food Allergy Safety, Treatment, Education, and Research (FASTER) Act of 2021 mandated sesame's addition, with mandatory labeling effective January 1, 2023. Sesame is present in a wide range of products — including tahini, hummus, baked goods, Asian cuisine preparations, and certain spice blends — making its identification on labels particularly important for the estimated 1.6 million Americans with sesame allergy. The nine allergens collectively recognized under FALCPA as amended by the FASTER Act are now commonly referred to as the "Big 9." Manufacturers were required to update their labels no later than January 1, 2023, for all products distributed in the United States.

How must allergens be declared on US packaged food labels?

FALCPA provides two compliant methods for allergen declaration on packaged food labels. The first method is a parenthetical statement within the ingredient list, where the common name of the allergen source appears in parentheses immediately after the ingredient name — for example, "semolina (wheat)" or "casein (milk)." The second method is a separate "Contains" statement placed immediately after or adjacent to the ingredient list — for example, "Contains: Wheat, Milk, Soy." When a "Contains" statement is used, it must include all major food allergens present in the product; a partial "Contains" statement that omits one or more allergens is not compliant. Both methods may be used simultaneously, but the declarations must be consistent — an allergen listed in the ingredient list must also appear in the "Contains" statement if that format is chosen. These requirements are established under Section 403(w) of the FD&C Act, which was added by FALCPA.

What rules govern precautionary allergen labeling in the United States?

Precautionary allergen labeling (PAL) — statements such as "May contain peanuts," "Manufactured in a facility that also processes tree nuts," or "Made on shared equipment with milk" — is voluntary under current United States federal regulations. The FDA has issued guidance discouraging the use of such statements when they are used as a substitute for good manufacturing practices, but PAL is not prohibited. Manufacturers who use PAL should ensure the statement reflects a genuine, assessed risk of cross-contact rather than a blanket disclaimer. The FDA's current Good Manufacturing Practice regulations at 21 CFR Part 117 establish the baseline hygiene and process controls that govern allergen cross-contact risk in food manufacturing facilities. Under these regulations, manufacturers must implement allergen controls as part of their food safety plans, including procedures to prevent cross-contact between allergen-containing and allergen-free product lines. The absence of a PAL statement does not certify that a product is allergen-free; it means only that no voluntary advisory has been added.

What are the EU's 14 regulated allergens under Regulation (EU) No 1169/2011?

The European Union mandates declaration of 14 allergen groups under Regulation (EU) No 1169/2011 on the provision of food information to consumers. These 14 allergens must be declared for both prepacked and non-prepacked (loose) foods sold in the EU, and must be emphasised in the ingredient list through a typographic distinction — bold, italic, or underlined text — so they stand out visually from other ingredients. The EU 14 are: cereals containing gluten (wheat, rye, barley, oats, spelt, kamut, and their hybridised strains), crustaceans, eggs, fish, peanuts, soybeans, milk, tree nuts (almonds, hazelnuts, walnuts, cashews, pecan nuts, Brazil nuts, pistachio nuts, and macadamia nuts), celery, mustard, sesame seeds, sulphur dioxide and sulphites (above 10 mg/kg or 10 mg/litre expressed as SO₂), lupin, and molluscs. Compared to the US Big 9, the EU framework adds celery, mustard, sulphites, lupin, and molluscs, and treats cereals containing gluten as a single category rather than identifying wheat specifically. Sulphites are included at concentrations above 10 mg/kg or 10 mg/litre.

How does cross-contact affect allergen labeling?

Cross-contact and cross-contamination are related but distinct concepts in allergen management. Cross-contact occurs when an allergenic food or ingredient transfers — physically or through shared surfaces, utensils, or airborne particles — to a food that is not intended to contain that allergen. The result is the unintentional introduction of an allergen into a product or dish at levels that may still cause a reaction in sensitive individuals. Cross-contamination is a broader term that encompasses microbial contamination as well as chemical and allergen contamination; in allergen-specific regulatory contexts, the FDA predominantly uses the term cross-contact. For food service operators, cross-contact risks arise from shared cooking surfaces, fryer oil, common utensils, improperly cleaned equipment, and staff handling multiple ingredients without changing gloves or washing hands. For manufacturers, 21 CFR Part 117 requires documented allergen control procedures specifically addressing cross-contact prevention.

How does the US allergen labeling decision flow work?

The following diagram summarises the labeling decision process for a packaged food product sold in the United States.

Does BetterMenu generate allergen declarations?

Not today. BetterMenu produces FDA Nutrition Facts panels. The allergen declaration is a separate mandatory label element under 21 CFR 101.4, and producing it remains your responsibility.

Custom ingredients accept an ingredient statement as free text. It is stored with the ingredient and returned through the API, but it is not parsed — no allergen set is matched, no "Contains" statement is composed, and no cross-contact flag is computed. An exported label artifact contains the nutrition panel only.

Treat this page as a regulatory reference for working out what your label must declare, and produce the declaration itself elsewhere.

Where can I find official allergen labeling resources?

• FDA - Where do allergen labeling requirements come from? (FALCPA & FASTER Act)
• FDA - Food Allergen Labeling Requirements of the United States (Section 403(w) FD&C Act)
• eCFR - 21 CFR 101.4 — Food; designation of ingredients
• eCFR - 21 CFR Part 117 — Current Good Manufacturing Practice, Hazard Analysis, and Risk-Based Preventive Controls for Human Food
• EU Regulation (EU) No 1169/2011 — Food Information to Consumers