The 9 Major Allergens and the FASTER Act

US law requires packaged foods to clearly declare nine major food allergens, and since January 1, 2023, sesame has been one of them. This guide explains which allergens are covered, how they must appear on the label, what the FASTER Act changed, and why "may contain" statements need a more careful read.

The nine major allergens

The Food Allergen Labeling and Consumer Protection Act of 2004 (FALCPA) identified eight foods that account for the vast majority of serious food allergic reactions in the US and required them to be clearly labeled, starting in 2006. The FASTER Act of 2021 (Food Allergy Safety, Treatment, Education, and Research Act) added sesame as the ninth, effective January 1, 2023. The nine are:

1. Milk
2. Eggs
3. Fish, such as bass, cod, or flounder
4. Crustacean shellfish, such as crab, lobster, or shrimp
5. Tree nuts, such as almonds, walnuts, or pecans
6. Peanuts
7. Wheat
8. Soybeans
9. Sesame

Other foods can cause serious reactions too, including mustard, celery, lupin, and molluscan shellfish like clams and oysters, but US law doesn't treat them as major allergens. They don't go in a "Contains" statement, and when they're used as a spice or flavoring, FDA rules (21 CFR 101.22(h)) allow them to be declared collectively as "spices" or "flavor" rather than by name, so people with these allergies may need to contact the manufacturer. Rules in other countries differ: the European Union, for example, requires labeling of 14 allergens.

How allergens must be declared

Under FALCPA, the food source of any major allergen must be identified in one of two ways:

In the ingredients list

The allergen's name can appear in parentheses after an ingredient whose name doesn't make the source obvious, such as "whey (milk)," "lecithin (soy)," or "flour (wheat)." If the ingredient name already includes the allergen, such as "wheat flour" or "milk," no extra parentheses are needed.

In a "Contains" statement

Alternatively, the label can use a statement that starts with the word "Contains," placed immediately after or next to the ingredients list, for example: "Contains: Milk, Wheat, Soy." If a company uses a "Contains" statement, it has to list every major allergen in the food.

Specific names are required

For tree nuts, fish, and crustacean shellfish, the label must name the specific type, such as "almonds," "cod," or "shrimp," not just "tree nuts" or "fish." The FDA has updated its guidance on which foods count as tree nuts over time; its 2025 guidance, for example, narrowed the list and no longer treats coconut as a tree nut.

Hidden sources are covered

The rule applies to allergens in flavorings, colorings, and incidental additives too. A "natural flavor" that contains milk protein, for example, must still be declared as milk.

What the FASTER Act changed

Before 2023, sesame could be hidden in terms like "spices" or "natural flavors" without being named. The FASTER Act made sesame a major allergen, so it must now be declared the same way as the original eight.

The change had an unintended effect. Because keeping sesame out of shared equipment can be costly, some manufacturers chose to intentionally add a small amount of sesame to products and label it, rather than guarantee the absence of sesame. The FDA noted that this practice is legal as long as the label is accurate, but it reduced the choices available to people with sesame allergy.

"May contain" statements are voluntary

Statements like "may contain peanuts," "processed in a facility that also processes tree nuts," or "made on shared equipment with milk" are called advisory or precautionary allergen labels. Unlike the "Contains" statement, they are voluntary and not defined by federal regulation. The FDA says they must be truthful and not misleading and must not be used as a substitute for good manufacturing practices, but there is no standard wording and no threshold that triggers them.

In practice, this means:

• A product with a "may contain" statement might have a real risk of cross-contact, or might carry it as a precaution.
• A product without one isn't guaranteed to be free of cross-contact.
• The different wordings don't reliably indicate different levels of risk.

People with severe allergies often avoid products with advisory statements for their allergen and contact the manufacturer when unsure.

What the law doesn't cover

• Meat, poultry, and some egg products are regulated by the USDA's Food Safety and Inspection Service, not by FALCPA, although allergen ingredients must still appear in the ingredients list.
• Most alcoholic beverages are regulated by the TTB, where allergen labeling is voluntary.
• Highly refined oils made from a major allergen, like refined peanut or soybean oil, are exempt from FALCPA labeling because refining removes most of the protein.
• Restaurant meals and food made to order aren't covered by the packaged-food labeling rules.

Undeclared allergens are one of the most common reasons for FDA food recalls, so it's worth re-reading labels on familiar products from time to time, since recipes change.

You can find current allergen recalls on the FDA's recalls page, and the FDA encourages consumers to report a reaction to a food, including a possibly undeclared allergen, through its Safety Reporting Portal or by calling the consumer complaint coordinator in their state.

How to use this on myfoodfact.com

• See products with the longest allergen declarations in our most allergens list.
• Browse products with no milk ingredients listed. It's built from each product's ingredient list and allergen statement, so cross-contact is still possible; check the package. Note that lactose intolerance and milk allergy are different conditions.
• See how soy is declared on a common emulsifier on our soy lecithin ingredient page.
• If you avoid wheat, read our guide to gluten-free labeling.

The bottom line

US packaged foods must clearly declare milk, eggs, fish, crustacean shellfish, tree nuts, peanuts, wheat, soybeans, and sesame, either in the ingredients list or in a "Contains" statement. That part of the label is regulated and reliable. "May contain" statements are voluntary and unstandardized, so treat them as a prompt for caution rather than a precise measure of risk, and always check the package in your hand, since allergen data online can lag behind recipe changes.

This guide is for general information and is not medical advice. If you have a food allergy, follow the guidance of your allergist, including any plan for emergency treatment.