What Allergens Must Be Listed on US Food Labels? 

A food allergy is an immune response that can be potentially serious or life-threatening. Reactions can happen within minutes or up to hours later. To help those with food allergies identify ingredients in packaged and prepared foods, the US requires that the nine most common allergens always be listed.

The most common allergens are: 

• eggs
• milk
• peanuts
• tree nuts (such as walnuts, coconuts and almonds)
• fish
• shellfish
• wheat
• soy
• sesame

There are three ways you might see allergens identified, according to the Food and Drug Administration. 

• The common name will be listed in the ingredient list. e.g., milk
• The label has a section labeled “contains,” followed by the name of the major allergen e.g., “Contains: milk”
• If a less common version of the ingredient is used, the common form is included in parentheses for clarity. e.g., “whey (milk)”

Potential food allergies should be diagnosed by a health care provider and taken seriously.