Food Allergen Labeling Requirements

US food allergen labeling requirements come from two laws: the Food Allergen Labeling and Consumer Protection Act (FALCPA) of 2004, and the FASTER Act, which made sesame the ninth major allergen effective January 1, 2023. Together they require that any packaged food containing one of the nine major allergens declare that allergen's food source in plain English, where a shopper can find it, either inside the ingredient list or in a separate “Contains” statement.

Getting this wrong is the most common reason food gets recalled. An allergen missing from the label, because of a reformulation, a supplier change, or the wrong label roll, is an undeclared-allergen recall, and those consistently lead FDA's recall counts. This post covers the nine allergens, the two ways FALCPA lets you declare them, when you need a parenthetical, what the “Contains” statement must include, and where advisory labeling fits.

What are the allergen labeling requirements in the US?

The requirement is simple to state and easy to violate: every major food allergen that is an intentional ingredient must have its food source named on the label using the source's common name. FALCPA, which added section 403(w) to the Federal Food, Drug, and Cosmetic Act, gives you two compliant ways to do it, and you must use at least one for every allergen present. The FDA FALCPA guidance spells both out:

• Ingredient-list declaration. Name the food source within the ingredient list, either because the ingredient name already contains it (“milk,” “peanuts”) or by adding it in parentheses after an ingredient whose name does not make the source clear (“lecithin (soy),” “natural flavor (milk)”).
• “Contains” statement. Place a separate statement immediately after or adjacent to the ingredient list, “Contains: Milk, Soy, Wheat.”, in type no smaller than the ingredient list.

Both apply to packaged foods regulated by FDA; USDA-regulated meat and poultry follow the same nine allergens through FSIS labeling policy. The declaration must use the specific food source: “tree nut” alone is not enough, you name the nut (almond, walnut). For fish and crustacean shellfish, you name the species (cod, shrimp).

What are the nine major food allergens?

The nine major food allergens are milk, eggs, fish, crustacean shellfish, tree nuts, peanuts, wheat, soybeans, and sesame. The first eight were named by FALCPA in 2004; sesame became the ninth through the FASTER Act, signed April 23, 2021 and effective January 1, 2023. All of the labeling and manufacturing requirements that apply to the original eight apply to sesame identically.

“Tree nuts” and “fish” are categories, not declarations. FDA expects the specific type, almond, walnut, or pecan for tree nuts; cod, bass, or flounder for fish; shrimp, crab, or lobster for crustacean shellfish. Milk, egg, peanut, wheat, soybean, and sesame each declare as themselves. Getting the specificity wrong is a surprisingly common finding, because a formulator writes “tree nut flavor” and never circles back to name the nut.

"Contains" statement vs ingredient-list declaration: which do you need?

You need at least one, not necessarily both, and the “Contains” statement is optional as long as every allergen source is already clear in the ingredient list. If you print a “Contains” statement, though, it must list every major allergen in the product, a partial statement that names some allergens but omits one does not satisfy FALCPA for the omitted allergen, even if that allergen appears by common name in the ingredient list. That trap catches plants that add a “Contains: Milk” line and forget the soy lecithin.

Most manufacturers use both belt and suspenders: correct in-list declaration plus a “Contains” statement, because it is the fastest thing for an allergic shopper to scan and it forces a deliberate reconciliation of every allergen. Decide which allergens need a parenthetical with a quick test.

What about advisory ("may contain") labeling?

Advisory labeling, “may contain peanuts,” “made in a facility that processes tree nuts”, is voluntary and addresses a completely different thing than the required declaration. Required labeling covers allergens you put in on purpose; advisory labeling flags the possibility of unavoidable cross-contact from shared equipment. FDA has stated advisory statements must be truthful and not misleading, and must not be used in place of good manufacturing practices, you cannot slap “may contain” on a product to avoid cleaning your line.

The practical rule: advisory labeling is a last resort, justified by a documented risk assessment, used only after segregation, scheduling, and validated cleaning have done everything they can. It is never a substitute for declaring an intentional allergen ingredient, and overusing it erodes its meaning for the shoppers who depend on it.

What about gluten-free and other "free-from" claims?

A “free-from” claim raises the bar from good practice to a verifiable, regulated statement. FDA defines “gluten-free” for labeling: a food bearing the claim must contain less than 20 parts per million of gluten, and while the claim is voluntary, it is enforceable once made. The same logic applies to any allergen-free or “no [allergen]” claim, making it converts your cross-contact program into something a regulator or certifier will test against, not just review on paper. If you cannot back the claim with validated controls and testing, do not make it.

Behind all of this sits one legal fact: a food that fails to declare a major allergen is misbranded under the FD&C Act, and undeclared allergens are among the most common reasons FDA requests a recall. Misbranding does not require anyone to get sick, the wrong label alone is the violation. That is why label control is treated as a food-safety control, not a marketing task, and why label reconciliation belongs in the same change-management process as a formula change or a supplier switch.

How do you build compliant allergen labels?

Build allergen labels from the formula outward, and reconcile them every time anything changes:

1. Map every allergen in the formula including allergens hidden inside compound ingredients, flavors, and processing aids, pulled from current supplier specifications.
2. Declare each source in the ingredient list, adding a parenthetical wherever the ingredient name does not make the food source clear.
3. Add a “Contains” statement if you use one, and confirm it lists every allergen in the product with none missing.
4. Check the specific-name rule: name the tree nut, the fish species, and the shellfish species, not just the category.
5. Assess cross-contact and decide, from a risk assessment, whether advisory labeling is warranted.
6. Reconcile at every changeover and every change: tie label approval to reformulations, supplier changes, and new SKUs so a recipe change can never ship on an old label.

That last step is where most recalls are actually prevented or caused. A label is correct the day it is designed; it becomes wrong when the recipe, a supplier, or the label stock changes and nobody re-checks. Building a hard link, no recipe change ships without a label review, no label prints without matching the current formula, is what keeps declared and actual allergens in agreement over months of production.

Common allergen labeling mistakes

The numbers behind the rule

• FALCPA added section 403(w) to the FD&C Act in 2004, requiring source-name declaration for the major allergens by ingredient list or a “Contains” statement (FDA FALCPA).
• Sesame became the ninth major allergen on January 1, 2023 under the FASTER Act, subject to the same labeling, GMP, and preventive-controls requirements as the other eight (FDA FASTER Act).
• Undeclared allergens are consistently a leading cause of FDA food recalls most often from labeling and changeover failures (FDA Food Allergies).

A label is only as good as the process that keeps it in sync with the recipe. The recalls in that last bullet almost never come from a misunderstanding of the law, they come from a reformulation, a supplier swap, or a label roll that nobody reconciled. Plants that link recipe changes, supplier specs, and label approval in one system catch the mismatch before it ships; those that manage them separately find out from a consumer complaint. Keeping the formula, the label, and the changeover check on the same live data is the plant-floor workflow Harmony runs, see a real plant on the floor. Behind every correct label sits an allergen management program and the GMPs that keep declared and actual in agreement, with a recall plan for the day they are not.