UK allergen
Mollusc allergy eating out in the UK
Molluscs are one of the 14 allergens: mussels, clams, oysters, scallops, squid, octopus, snails and whelks. Oyster sauce is a common hidden source. Prawns are crustaceans, and a kitchen can avoid one list while still using the other.
Oyster sauce is the frequent miss
Molluscs include mussels, clams, oysters, scallops, squid, octopus, snails and whelks. The animal on a seafood platter is obvious. Oyster sauce in a stir-fry is not, and it appears in dishes that otherwise look like noodles and vegetables. If oyster sauce is a problem, say the sauce by name.
Squid and octopus are molluscs, which surprises people who use “shellfish” to mean prawns. A fried calamari starter and a sauce made with mussel juices are the same allergen group, even though one has a shell and one does not.
Keep crustaceans as a second list
Prawns, crab and lobster are crustaceans, not molluscs. UK law lists them separately. A kitchen can honour “no mussels” and still cook with prawn stock. Tell them both groups if you need both left out. Fish is a third list.
Mixed seafood rice and stews are built from shared pots. If cross-contact matters, ask whether your portion can be cooked apart from the mussel or squid order. There is no national rule that a restaurant must keep a mollusc-free pan, so the answer will be local.
Declarations
Molluscs are one of the 14. On food packed before you choose it, Natasha’s Law requires the ingredients, with molluscs emphasised if they are in the product. On a cooked stir-fry, you need the cook to know whether the house sauce contains oyster extract.
SafePlate will leave the mollusc score unknown until a menu or a visitor note mentions molluscs. Add them to your profile under their own name so a prawn setting does not stand in for them.
What to ask about molluscs
- Is there oyster sauce, mussel, clam, squid or octopus in this dish or the sauce?
- Is the stock a seafood stock, and which animals are in it?
- Can my food be cooked away from the mussel or squid pans?
- Do you also need to keep prawns and crab out, or only molluscs?
- If there is a bottle of sauce, can you read whether it contains oyster?
Search with molluscs on your profile
Record molluscs separately from prawns. Search a city, and ask about oyster sauce even when the plate is not a seafood platter.
Questions people ask
Is squid a shellfish?
In UK allergen terms, squid is a mollusc. Prawns are crustaceans. If you say shellfish, also say which of those you mean. Squid and oyster sauce are easy to leave out of a prawn-only warning.
Is oyster sauce always made with oysters?
The traditional sauce is made with oysters. Some products are made differently. Ask about the bottle in that kitchen rather than assuming from the name alone, and ask them to read it if they are unsure.
How do I search for this on SafePlate?
Add molluscs to your profile, and crustaceans or fish if you avoid those too. Search the city. An Unknown score means there is no menu note on file, so ask before you order.
Set up your foods before you search. This is not medical advice. Confirm the meal with the kitchen. If you think someone is having anaphylaxis, call 999.