FALCPA & the Big 9 Allergens: US Food Allergen Labeling Explained

What FALCPA is and why it exists

FALCPA stands for the Food Allergen Labeling and Consumer Protection Act of 2004. It is the US federal law that requires packaged food regulated by the Food and Drug Administration (FDA) to clearly declare the major food allergens it contains. The law was passed in 2004 and took effect on January 1, 2006. It applies to FDA-regulated packaged foods — which covers the large majority of retail and many food service packaged products, though meat, poultry and certain egg products fall under USDA rules instead.

Before FALCPA, allergens could legally hide in plain sight. A consumer with a milk allergy scanning an ingredient list might see "casein," "whey" or "sodium caseinate" without realizing those are milk-derived. Someone allergic to wheat might not recognize "semolina" or "spelt." Vague catch-all terms such as "natural flavor" or "spices" could conceal an allergenic ingredient entirely. FALCPA closed that gap by requiring that major allergens be identified by their common food source name — milk, wheat, soy — in language an ordinary shopper can understand.

The practical consequence for any food business is simple: it is not enough for your label to be technically accurate to a food scientist. It has to be clear to a consumer with a serious allergy who is reading the label in a hurry. That shift in standard — from technically correct to plainly understandable — is the heart of FALCPA, and it is the principle that every other rule in this article builds on. FoodCore supports this through its FALCPA allergen labeling software, which keeps each ingredient's allergen data attached to the recipes that use it.

The original 8 — and how sesame made it the Big 9

When FALCPA was enacted in 2004, it named eight major food allergens. These eight were understood to account for the overwhelming majority of serious allergic reactions in the United States:

• Milk
• Eggs
• Fish
• Crustacean shellfish
• Tree nuts
• Peanuts
• Wheat
• Soybeans

For nearly two decades, those eight defined US allergen labeling. That changed with the FASTER Act — the Food Allergy Safety, Treatment, Education, and Research Act. The FASTER Act added sesame as the ninth major food allergen, and the requirement to declare it became effective on January 1, 2023. From that date, sesame must be declared on the labels of FDA-regulated packaged foods in exactly the same way as the original eight.

With sesame added, the nine major allergens are now commonly referred to as the "Big 9": milk, eggs, fish, crustacean shellfish, tree nuts, peanuts, wheat, soybeans and sesame. If your business labels packaged food for the US market, these nine are the allergens you must track and declare. We cover the sesame change in depth in our dedicated guide to the FASTER Act and sesame labeling.

The Big 9 allergens at a glance

The table below summarizes the nine major US allergens, with examples of where they appear and how they should be named on a label. Note the important distinction in the right-hand column: for fish, crustacean shellfish and tree nuts, the specific species or type must be declared, not just the broad category.

Why the species-level rule for fish, crustacean shellfish and tree nuts? Because allergic individuals are frequently sensitive to specific species. A person allergic to walnuts may tolerate almonds; someone allergic to shrimp may not react to crab. Declaring only "tree nut" or "shellfish" deprives them of the information they need to make a safe choice — so FALCPA requires the specific name, such as "cod," "shrimp" or "almond."

The two acceptable ways to declare allergens

FALCPA does not require a single fixed format. Instead it gives food businesses two acceptable methods for declaring major allergens on a label. You may use either, but whichever you choose must cover every major allergen present in the product.

Method 1: declaration within the ingredient list

The food source name of the allergen can appear directly within the ingredient list, in parentheses immediately after the ingredient that contains it. For example: "Ingredients: enriched flour (wheat), sugar, whey (milk), soy lecithin." Here the allergen identity is attached to each relevant ingredient, so the consumer can see at a glance which components introduce which allergens.

If the ingredient is already named by its common food source name — "milk," "peanuts," "eggs" — no parenthetical is needed because the source is already obvious. The parenthetical is required when the ingredient name alone would not make the allergen clear, such as "whey," "semolina" or "albumin."

Method 2: a "Contains" statement

Alternatively, you can place a separate "Contains" statement immediately after or directly adjacent to the ingredient list. For example: "Contains: Wheat, Milk, Soy." This single line summarizes every major allergen in the product. If you use a Contains statement, the rule is strict: it must list every major allergen present in the food. You cannot list some and omit others, and the allergens named must match what is actually in the ingredient list.

In practice many manufacturers use a Contains statement because it is the clearest format for consumers — a single, scannable line. But it is not a shortcut that lets you skip accurate ingredient declarations; the ingredient list must still be complete and correct, and the Contains statement must be consistent with it.

Plain-language and common-name requirements

The thread running through both methods is the plain-language requirement: the allergen must be declared using the common name of the food source in everyday English. "Milk," not just "casein." "Wheat," not just "durum." "Soy," not just "lecithin" without qualification. The goal is that a consumer with no scientific background can read the label and immediately recognize the allergen.

This matters most for ingredients whose names do not obviously reveal their source. Consider a few examples a small producer might overlook:

• Whey, casein, sodium caseinate — all derived from milk; must be tied to "milk."
• Albumin — commonly egg-derived; must be tied to "egg" where applicable.
• Semolina, durum, spelt, farina — forms of wheat; must be tied to "wheat."
• Tahini — made from sesame; the sesame source must be clear.
• Surimi — typically made from fish; the specific fish should be named.

Because this kind of source-tracking is exactly where manual labeling goes wrong, software that keeps allergen data attached to each ingredient is valuable. FoodCore's US food labeling software stores the food-source allergen for every ingredient so the correct common name flows through to your products — though you remain responsible for confirming each declaration is accurate.

Advisory "may contain" statements: voluntary, not a substitute

Beyond the mandatory declaration of allergens that are deliberately in the product, many labels also carry an advisory or precautionary allergen statement — wording such as "may contain peanuts," "produced in a facility that also processes tree nuts," or "manufactured on shared equipment with milk." These communicate the risk of unintended allergen presence arising from cross-contact during production.

Two points are essential to understand. First, in the United States these advisory statements are voluntary. FALCPA does not require them and does not regulate their exact wording. Second — and this is the part businesses most often get wrong — a precautionary statement is never a substitute for controlling cross-contact. You cannot manage a real contamination risk simply by printing "may contain" on the label and carrying on. The FDA expects businesses to actually control cross-contact through cleaning, scheduling and segregation, and to reserve advisory wording for situations where a genuine, unavoidable risk remains after those controls are in place.

Cross-contact vs cross-contamination

These two terms are often used interchangeably, but in allergen management the distinction matters.

Cross-contact is the unintentional transfer of an allergenic protein from one food to another — for example, mixing a wheat-based batter and then using the same unwashed mixer, spatula or work surface for a product that is supposed to be wheat-free. Even a trace amount of transferred protein can trigger a serious reaction in an allergic person, and unlike bacteria, cooking does not reliably destroy the allergen. Heat denatures many microorganisms but does not make an allergenic protein safe.

Cross-contamination, by contrast, generally refers to the transfer of harmful microorganisms — bacteria, viruses — that cause foodborne illness. Many of these can be reduced or eliminated by proper cooking temperatures.

For allergen compliance, the concept that matters is cross-contact, and it is controlled through operational discipline:

• Dedicated or thoroughly cleaned equipment for allergen-containing and allergen-free production.
• Production scheduling — running allergen-free products first, before allergen-containing ones, then cleaning down.
• Physical separation of ingredients in storage to prevent spills and mix-ups.
• Staff training so the whole team understands why a quick wipe-down is not the same as a full clean.

These controls — not a label disclaimer — are what actually protect an allergic consumer. The label communicates; the controls protect.

Where FoodCore fits — and where it does not

FoodCore is kitchen-management software that helps food businesses manage recipes, costing and labeling, including for the US market. It includes a Compliance Region setting (UK, US, or Both) so you can put the platform into US (Big 9) mode and have it track the nine major US allergens across your recipes. Here is an honest picture of what it does and does not do.

What it does. FoodCore stores the food-source allergen for each ingredient and propagates that data automatically through nested sub-recipes to your finished products, so when an ingredient's allergen profile changes, every affected product is flagged. Its AI assistant reasons under the FDA, FALCPA and FASTER Act framework to help you spot likely issues — such as an allergen that appears in an ingredient but is missing from a Contains statement. It is a capable assistant that helps you catch problems faster.

What it does not do. The AI assistant is not a curated, definitive legal checker and should not be treated as the final word on compliance — it reasons and flags; it does not certify. Similarly, FoodCore's label designer does not automatically enforce descending-weight ingredient order, dual net-quantity declarations, or "Distributed by" wording. Those elements are your responsibility to arrange correctly on the label. FoodCore gives you the data and the tools; you remain the compliance decision-maker.

If your priority is the nutrition panel rather than the allergen declaration, see our FDA Nutrition Facts label software and the broader US compliance software overview. To work out pricing for your products before you label them, the recipe cost calculator is a free starting point.

A practical checklist for US allergen labeling

Before any packaged product goes to market, run through the essentials:

• Have you identified every one of the Big 9 allergens present, including sesame?
• Is each allergen declared by its common food source name in plain English?
• For fish, crustacean shellfish and tree nuts, have you declared the specific species or type?
• If you use a Contains statement, does it list every major allergen and agree with the ingredient list?
• Are your cross-contact controls documented and in place — not replaced by a "may contain" disclaimer?
• When a supplier reformulates an ingredient, do you have a process to re-check and update affected labels before sale?

For a fuller walkthrough of building a compliant label end to end, see how to create an FDA-compliant food label and our guide to FDA Nutrition Facts requirements for small businesses.

Frequently asked questions

Further resources

• FDA — Food Allergen Labeling and Consumer Protection Act (FALCPA) Questions and Answers
• The FASTER Act & sesame labeling
• How to create an FDA-compliant food label
• FDA Nutrition Facts label requirements for small businesses
• FDA vs UK food labeling: a comparison
• FoodCore FALCPA allergen labeling software
• FoodCore US food labeling software
• FoodCore FDA Nutrition Facts label software
• FoodCore US compliance software