U.S. flag An official website of the United States government
  1. Home
  2. For Consumers
  3. Consumer Updates
  4. Have Food Allergies? Read the Label
  1. Consumer Updates

Have Food Allergies? Read the Label



Food labels can help consumers with food allergies avoid foods or ingredients that they or their families are allergic to.

This is because a federal law, the Federal Food, Drug and Cosmetic Act, requires that the labels of most packaged foods marketed in the U.S. disclose — in simple-to-understand terms — when they are made with a “major food allergen.”

Nine foods, and ingredients containing their proteins, are defined as major food allergens. These foods account for the large majority of severe food allergic reactions:

  • milk
  • egg
  • fish, such as bass, flounder, or cod
  • Crustacean shellfish, such as crab, lobster, or shrimp
  • tree nuts, such as almonds, pecans, or walnuts
  • wheat
  • peanuts
  • soybeans
  • sesame

The law requires that food labels identify the food source of all major food allergens used to make the food. This requirement is met if the common or usual name of an ingredient already identifies that allergen's food source name (for example, buttermilk). Otherwise, the allergen's food source must be declared at least once on the food label in one of two ways.

The name of the food source of a major allergen must appear:

In parentheses following the name of the ingredient.

Examples: "lecithin (soy)," "flour (wheat)," and "whey (milk)"


Immediately after or next to the list of ingredients in a "contains" statement.

Example: "Contains Wheat, Milk, and Soy."

The “Contains” statement, if present, must list all allergens that are in the product. “So, if a ‘Contains’ statement has your allergen listed, put the food product back on the shelf,” says Carol D'Lima, food technologist with the Office of Nutrition and Food Labeling at the U.S. Food and Drug Administration.

However, not all allergen-containing products have a “Contains” statement. So, to be sure that an allergen is not present, consumers should always read all ingredient information on the label. “It’s very important to read the entire ingredient list to see if your allergen is present. If you see its name even once, it’s back to the shelf for that food product too.”

There are many different ingredients that contain the same major food allergen, but sometimes the ingredients’ names do not indicate their specific food sources. For example, casein, sodium caseinate, and whey are all milk proteins. Although the same allergen can be present in multiple ingredients, its “food source name” (for example, milk) must appear in the ingredient list just once to comply with labeling requirements.

Sesame was not a major food allergen under the Food Allergen Labeling and Consumer Protection Act of 2004. Sesame became the ninth  major food allergen in 2021 with the signing of the Food Allergy Safety, Treatment, Education and Research (FASTER) Act. As of January 1, 2023, sesame is required to be labeled as an allergen on food packages, including dietary supplements.  

Even though the requirement that sesame be listed on the label as an allergen is in effect as of January 1, 2023, you still may find food products for sale that don’t list sesame as an allergen on the label. 

The law does not require food products that were already on their way to the store or in stock before 2023 to list sesame as an allergen on the label. So for now, consumers may still want to check with the manufacturer.

Allergen labeling requirements for foods that aren’t packaged may vary, like bagels in a grocery bin or bakery goods displayed on trays. If you’re concerned about those products, you may want to ask store personnel for food allergen information. 

"Contains" and "May Contain" Have Different Meanings 

If a “Contains” statement appears on a food label, it must include the food source names of all major food allergens used as ingredients. For example, if “whey,” “egg yolks,” and a “natural flavor” that contained peanut proteins are listed as ingredients, the “Contains” statement must identify the words “milk,” “egg,” and “peanuts.”

Some manufacturers voluntarily include a separate advisory statement, such as “may contain”  or "produced in a facility," on their labels when there is a chance that a food allergen could be present. A manufacturer might use the same equipment to make different products. Even after cleaning this equipment, a small amount of an allergen (such as peanuts) that was used to make one product (such as cookies) may become part of another product (such as crackers). In this case, the cracker label might state “may contain peanuts.”

Be aware that the “may contain” statement is voluntary, says D'Lima. “Not all manufacturers use it.”

When in Doubt, Leave It Out

A food product's ingredients can be changed at any time, so D'Lima says it’s a good idea to check the label every time you buy the product — even if you have eaten it before and didn’t have an allergic reaction.

“If you’re unsure about whether a food product contains any ingredient to which you are sensitive, don’t buy it, or check with the manufacturer or distributor listed on the food product's label first to ask what it contains," says D'Lima. 


Consumer Updates Email

Subscribe to receive Consumer Updates email notifications.

Back to Top