Food allergen labels explained

Most packaged foods sold in the US must say on the label when they contain a major food allergen.² The label names each allergen’s food source at least once, either in the ingredient list or in a “Contains” statement.¹ Warnings such as “may contain” work differently: FDA says they are not required by law.¹

The nine major food allergens

The federal list began with the Food Allergen Labeling and Consumer Protection Act of 2004, known as FALCPA, approved on August 2, 2004.⁴ It named eight foods or food groups: milk, eggs, fish, crustacean shellfish, tree nuts, peanuts, wheat and soybeans.⁴ In the law, Congress found that these eight account for 90 percent of food allergies, and its labeling rules apply to foods labeled on or after January 1, 2006.⁴

Sesame came later. The FASTER Act, signed on April 23, 2021, made sesame the ninth major food allergen, and the change took effect on January 1, 2023.¹ Products already in interstate commerce before that date, such as those on retail shelves, did not need to be removed from the market or relabeled, and FDA says some products may not carry allergen labeling for sesame right away.¹

AllergyNest has a page on each one: milk, egg, fish, shellfish, tree nuts, peanut, wheat, soy and sesame.

Small amounts count. FARE notes that manufacturers must list a FALCPA allergen even if the amount is very small.¹¹ ACAAI adds that the allergen must be stated even when it is only an incidental ingredient, as in an additive or flavoring.¹⁰ FDA says it has not established a threshold level for any allergen.¹

Two ways a label can name an allergen

Under the law, each major allergen’s food source must appear on the label at least once, in one of two ways.¹ The first is in parentheses after an ingredient’s name, as in “lecithin (soy),” “flour (wheat)” or “whey (milk).”³ The second is a “Contains” statement placed right after or next to the ingredient list, such as “Contains Wheat, Milk, and Soy.”³ The law requires that statement to be in type no smaller than the type used in the ingredient list.⁴

FDA guidance, citing the law, says that when a label uses a “Contains” statement, the food sources of all the major allergens in the product are to be declared there, even those already named in the ingredient list.⁵ No extra wording is needed when an ingredient’s common name already identifies its source, such as buttermilk for milk.³

Tree nuts, fish and shellfish by name

For three groups, the label has to be more specific, and FDA gives these examples.¹

Allergen group	What the label must name	Examples
Tree nuts	The type of tree nut	Almonds, pecans, walnuts
Fish	The species of fish	Bass, flounder, cod
Crustacean shellfish	The species of shellfish	Crab, lobster, shrimp

FDA guidance says this means neither the ingredient list nor the “Contains” statement can broadly declare “tree nuts,” “fish” or “Crustacean shellfish” as the allergen.⁵ For fish and crustacean shellfish, the guidance says the ingredient list should use the acceptable market name or common name from FDA’s Seafood List, while a “Contains” statement may also use a generic name, such as “salmon” for chum salmon.⁵ Not every shellfish is a major allergen. Molluscan shellfish, such as oysters, clams, mussels and scallops, are not.⁵

What changed in January 2025

FDA published a revised edition of its allergen labeling guidance on January 6, 2025.⁶ Guidance describes FDA’s current thinking. In general, it does not establish legally enforceable responsibilities and should be viewed only as recommendations, unless specific regulatory or statutory requirements are cited.⁵

In the revision, FDA concluded that only the tree nuts in Table 1 of the guidance are tree nuts it considers major food allergens.⁶ That table lists almond, black walnut, Brazil nut, California walnut, cashew, filbert or hazelnut, heartnut or Japanese walnut, macadamia nut or bush nut, pecan, pine nut or pinon nut, pistachio, and English or Persian walnut.⁵ Coconut is no longer on the list, nor are beech nut, butternut, chestnut, chinquapin, cola or kola nut, ginkgo nut, hickory nut, palm nut, pili nut, shea nut and lichee nut.⁶ FDA says these nuts must still be listed in the ingredient list when added as ingredients, unless an exemption applies, but should not appear in the “Contains” statement, which is reserved for major food allergens.⁶

The same revision expanded FDA’s interpretation of milk and eggs.⁶ FDA now considers milk to be milk from domesticated cows, goats, sheep or other ruminants, and eggs to be eggs from domesticated chickens, ducks, geese, quail and other fowl.⁶ For milk from an animal other than a cow, the guidance says the label should also name the animal, as in “whey (goat milk).”⁵

What the labeling law leaves out

FDA enforces the law in most packaged foods, including dietary supplements.¹ FDA says this does not include meat, poultry and egg products, which the US Department of Agriculture regulates, or alcoholic beverages subject to Alcohol and Tobacco Tax and Trade Bureau labeling regulations.¹ Raw agricultural commodities, highly refined oils, drugs, cosmetics and most foods sold at retail or food service establishments that are not prepackaged with a label are also outside it.¹ Highly refined oils are exempt from the allergen section of the law, but under general ingredient labeling rules the source of every oil must still appear in the ingredient list as part of its name, as in “soybean oil.”⁵

Under the Federal Meat Inspection Act, the Poultry Products Inspection Act and the Egg Products Inspection Act, every ingredient used to make a meat, poultry or egg product must be declared in its ingredients statement.⁷ USDA’s Food Safety and Inspection Service (FSIS) has accepted a voluntary statement such as “Contains: milk, wheat gluten, soy” placed right after the ingredients statement.⁷

Allergens outside the federal list, such as mustard, may be missing from an ingredient list when they are part of a spice or flavoring, FARE notes, and may be covered instead by a general term such as “natural flavorings.”¹¹

Where “may contain” fits

Some packages carry precautionary statements such as “may contain,” “might contain,” “made on shared equipment” or “made in a shared facility.”¹⁰ FDA says such statements are not required by law and can be used to address unavoidable cross-contact only if manufacturers have incorporated good manufacturing processes and taken every precaution to avoid cross-contact.¹ FDA adds that its guidance and regulations for the food industry say these statements should not be used as a substitute for current good manufacturing practices and must be truthful and not misleading.¹ FDA guidance notes that the allergen section of the law does not address them.⁵ ACAAI says there are no laws or regulations requiring these warnings and no standards that define what they mean.¹⁰

FDA guidance also says a product with a “Contains milk” statement should not also carry a “may contain milk” statement, and a product with an allergen-free claim, such as “milk-free,” should not carry an advisory statement for the same allergen.⁵ FARE notes that free-from phrases such as “peanut-free” and “egg-free” are not regulated.¹¹

For meat, poultry and egg products, FSIS guidance says statements such as “may contain peanuts” may be used only where an establishment shows that adequate sanitation procedures cannot effectively eliminate cross-contact, and not as a replacement for poor sanitation procedures.⁷

When a label leaves an allergen out

FDA considers a food whose label lacks required allergen information misbranded or adulterated, depending on the circumstances, and subject to enforcement actions such as recalls, import refusal and seizure.¹ When a problem justifies a recall, firms generally recall the food voluntarily, and FDA works with firms on the recall and on public notification.¹ FDA says that of the major food allergens, milk is the most common cause of recalls for undeclared allergens.¹

For meat, poultry and egg products, an FSIS directive says FSIS may request that an establishment voluntarily recall the affected product when one of the “Big 9” food allergens is not properly declared.⁸ In calendar year 2023, FSIS counted 65 recalls, and 15 of them were for undeclared allergens.⁹

ACAAI’s advice for questions about which foods are safe to eat is to talk with an allergist.¹⁰