Hidden names for fish and shellfish on labels
In short: Fish and shellfish hide in anchovy-based sauces (Worcestershire, Caesar dressing), fish sauce, oyster sauce, shrimp paste, dashi, surimi, krill oil and some supplements. The EU lists fish, crustaceans and molluscs as three separate allergens. US labels must name the fish or crustacean species, but molluscs such as squid, oyster and mussel are not major allergens there.
Key facts
- EU law treats fish, crustaceans and molluscs as three separate allergens that must be emphasised.
- US labels must name the species of fish or crustacean; molluscs are not major allergens in the US.
- Worcestershire sauce, fish sauce, oyster sauce, shrimp paste, dashi and surimi often contain fish or shellfish.
- Fish and shellfish allergies involve different proteins, so an allergy to one does not always mean an allergy to the other.
Fish and shellfish allergies are among the food allergies most likely to start in adulthood and to last for life. A fillet of salmon or a plate of prawns is easy to avoid. The harder part is the anchovy in a sauce, the shrimp paste in a curry or the krill in a supplement capsule.
Three allergen groups, not one
"Shellfish" covers two unrelated groups, and labels treat them differently:
| Group | Examples | EU / UK | US |
|---|---|---|---|
| Fish | anchovy, cod, tuna, salmon, pollock, sardine, bonito | allergen, must be emphasised | major allergen, species must be named |
| Crustaceans | shrimp, prawn, crab, lobster, crayfish, langoustine, krill | allergen, must be emphasised | major allergen, species must be named |
| Molluscs | mussel, oyster, clam, scallop, squid, octopus, cuttlefish, snail | allergen, must be emphasised | not a major allergen |
- EU and UK: fish, crustaceans and molluscs are three of the 14 allergens. They must be emphasised in the ingredient list, for example "Worcestershire sauce (anchovies)".
- US: fish and crustacean shellfish are two of the 9 major allergens. The label must name the species, such as "cod" or "shrimp", not just "fish". Molluscs only appear in the ingredient list by name.
Names that mean fish
- any fish species: anchovy, sardine, pilchard, herring, mackerel, tuna, bonito, cod, pollock, hake, haddock, salmon, trout, tilapia, catfish, eel
- roe, caviar, bottarga, taramasalata
- fish sauce (nam pla, nước mắm, patis), fish stock, fish paste, fish extract, fish flavouring
- katsuobushi (dried bonito flakes) and dashi stock
- fish gelatine, fish collagen or marine collagen, fish oil, cod liver oil, omega-3 from fish
- surimi (usually pollock or other white fish)
- isinglass (a fining agent from fish bladders)
Names that mean shellfish
Crustaceans:
- shrimp, prawn, scampi, langoustine, crab, lobster, crayfish or crawfish, krill
- shrimp paste (belacan, kapi, terasi), dried shrimp, shrimp powder, prawn crackers
- crab extract, lobster bisque, shellfish stock, seafood flavouring
Molluscs:
- mussel, oyster, clam, cockle, scallop, whelk, abalone
- squid (calamari), octopus, cuttlefish, squid ink (in black pasta and risotto)
- snail (escargot)
- oyster sauce, clam juice (in some tomato cocktail drinks), XO sauce (dried scallop and shrimp)
Foods where fish and shellfish often hide
- Worcestershire sauce and dishes made with it (Bloody Mary, some barbecue sauces and burgers)
- Caesar dressing, tapenade, puttanesca sauce, salsa verde and some pizza toppings (anchovies)
- Asian sauces and pastes: fish sauce, oyster sauce, shrimp paste in Thai and Malaysian curry pastes, XO sauce, many dipping sauces
- Kimchi, which is often made with fish sauce or salted shrimp
- Japanese stocks and soups: dashi, miso soup, ramen broth, furikake seasoning (often bonito)
- Surimi and crab sticks: fish, and sometimes crab flavouring or real crab, plus egg white (see hidden egg)
- Paella, gumbo, bouillabaisse, seafood risotto and "seafood" pizza
- Supplements: fish oil, cod liver oil, krill oil (a crustacean), and glucosamine or chitosan, which are often made from crab or shrimp shells. Check the source on the pack and ask your doctor.
- Flavour enhancers: disodium inosinate (E631) and disodium guanylate (E627) are mostly made by fermentation, but can come from fish. The source is not always stated.
"Natural flavour" on a US label can, in rare cases, include fish or shellfish extracts; see can natural flavors contain allergens?.
Exemptions to know about
EU law exempts two fish ingredients from allergen labelling because they are so highly processed:
- fish gelatine used as a carrier for vitamin or carotenoid preparations
- fish gelatine or isinglass used to clarify beer and wine
So a beer or wine fined with isinglass does not have to say "fish". If you react to tiny amounts, ask your allergist whether this matters for you, and look for drinks marked vegan, which are not fined with animal products.
Cross-contact and eating out
Fish and shellfish are often cooked in shared fryers, on shared griddles and in the same water or stock. Restaurants that serve seafood may use one fryer for calamari, battered fish and chips. Some people also react to steam or vapour from cooking fish or shellfish. Ask how dishes are cooked, not only what is in them. A restaurant allergy card helps abroad, especially in coastal and East Asian cuisines where fish sauce and shrimp paste are everyday seasonings.
"May contain fish" or "may contain crustaceans" lines are voluntary and have no legal threshold. See what "may contain" means.
Fish allergy vs shellfish allergy
- Fish allergy is mostly caused by a protein called parvalbumin, which is similar in many fish species. Many people allergic to one fish react to others, but some tolerate certain species. Canned tuna or salmon is sometimes tolerated because heat changes the proteins; only try this under an allergist's guidance.
- Crustacean allergy is mostly caused by tropomyosin. People allergic to shrimp often react to crab and lobster too. Related proteins in molluscs, dust mites and insects can also cause cross-reactions.
- An allergy to fish does not automatically mean an allergy to shellfish, or the other way round. Your allergist can test which groups you need to avoid.
Beyond food
Fish and shellfish ingredients also turn up in cosmetics and medicines:
- marine collagen or hydrolysed fish collagen in creams and drinks
- guanine (CI 75170), a shimmer pigment made from fish scales, in nail polish and eye shadow
- chitosan from crustacean shells in some hair and skin products
- squalane or squalene, which was traditionally made from shark liver; most is now plant-based, but the label rarely says which
Our guide to cosmetic ingredient lists explains how to read INCI names.
How IngrediLens helps
With fish, crustacean or mollusc filters, IngrediLens highlights these allergens and their other names, such as anchovy, bonito, surimi, krill, shrimp paste, squid and oyster sauce, on food and cosmetic labels. It also flags "may contain" lines separately. The free version includes 2 filters, and it reads labels in six languages, which helps with imported Asian sauces and holiday shopping. The app can miss words, so always read the pack as well.
Ingredient glossary: anchovy, fish sauce, fish gelatin, shrimp and prawn, molluscs, cod liver oil.
Check labels with IngrediLens
Point your iPhone camera at an ingredient list and IngrediLens highlights the allergens you chose and “may contain” statements. Free to start, no account, and your data stays on your device.
Download on the App StoreFrequently asked questions
What are hidden sources of fish on food labels?
Common ones are anchovies in Worcestershire sauce, Caesar dressing, tapenade and pizza toppings; fish sauce (nam pla, nước mắm) in Asian dishes and some kimchi; bonito in dashi stock; surimi in crab sticks; and fish gelatine, fish oil or fish collagen in sweets, supplements and drinks.
Is squid or oyster sauce a shellfish allergen?
Squid, octopus, oyster, mussel, clam and scallop are molluscs. In the EU and UK molluscs are one of the 14 allergens and must be emphasised. In the US they are not major allergens, so they are named in the ingredient list but are not flagged in the "Contains" line.
If I am allergic to shrimp, am I allergic to all shellfish?
Many people allergic to one crustacean, such as shrimp, also react to crab and lobster, because they share a protein called tropomyosin. Reactions to molluscs are less predictable. Your allergist can tell you which groups you need to avoid.
Is shellfish allergy the same as iodine allergy?
No. Shellfish allergy is a reaction to proteins in shellfish, not to iodine. Allergy organisations advise that it is not by itself a reason to avoid iodine-based contrast dye or iodine antiseptics, but tell your doctor about any allergy before a procedure.
