Shellfish in the United States: label rules and introduction guidance

Is shellfish on the FDA's list of 9 major food allergens?

This is the biggest difference between the US list and most others. FDA's Edition 5 guidance answers the question directly: Crustacean shellfish, such as crab, lobster or shrimp, are major food allergens, but molluscan shellfish, such as oysters, clams, mussels or scallops, are not. For crustaceans, the species must be named, so the label says 'shrimp' or 'crab' rather than 'shellfish'. Molluscs still appear in the ingredient list under their common name, but they are not part of the 'Contains' statement. If you are checking a US product for a mollusc, the ingredient list is the only place to look.

In the United States, the Federal Food, Drug, and Cosmetic Act, as amended by the Food Allergen Labeling and Consumer Protection Act (FALCPA) and the FASTER Act, names nine major food allergens: milk, eggs, fish, Crustacean shellfish, tree nuts, peanuts, wheat, soybeans and sesame. A packaged food has to declare each one either in parentheses after an ingredient, such as 'whey (milk)', or in a 'Contains' statement printed immediately after or next to the ingredient list.

• FDA: Food Allergies
• FDA: Questions and Answers Regarding Food Allergens (Edition 5, January 2025)

What CDC guidance says about introducing shellfish

CDC names shellfish in its short list of potentially allergenic foods and advises introducing them when you introduce other foods. That advice does not separate crustaceans from molluscs, even though the US label rule does. The NIAID addendum covers peanut only. Shellfish is rarely among the first foods families reach for, and preparation matters for a baby, so your paediatrician can help you decide when and how to try it, especially if there is a seafood allergy in the family.

US advice on first foods comes from several places. CDC's page for parents says to introduce potentially allergenic foods when you introduce other foods. For peanut specifically, an expert panel sponsored by the National Institute of Allergy and Infectious Diseases (NIAID) published addendum guidelines in 2017. Neither replaces a conversation with your paediatrician about your own baby.

• CDC: When, What, and How to Introduce Solid Foods

Logging shellfish in the app

Set your region to the United States and the app's allergen schedule follows the FDA's nine. In the schedule, shellfish appears as Shellfish. Each allergen entry moves from not started to introduced, cleared or reaction, and the 14-day window keeps new foods spaced out so a delayed reaction is easier to match to a food. Log prawn, crab or mussel by name, because crustaceans and molluscs are different allergen groups in most countries. If you see a symptom, log it with its severity; the paediatrician report gathers the dates into one PDF for your next appointment. It is a record for you and your doctor, not a diagnosis.