Allergen 8 of 14 · Mo
Molluscs: the oyster sauce in the stir fry
Molluscs are the soft-bodied shellfish: mussels, oysters, clams, cockles, whelks, scallops, and also squid, octopus and snails. The one most often missed is oyster sauce.
Checked against the official guidance on 18 September 2026
What the law covers
Annex II lists “molluscs and products thereof”. It is a separate allergen from crustaceans.
Where it hides in a UK kitchen
| Where | Why |
|---|---|
| Oyster sauce | Made from oyster extract, in many Chinese stir fries and noodle dishes. |
| Calamari and squid | Squid is a mollusc, including in a battered starter. |
| Paella and seafood mixes | Mussels and squid, often next to prawns (a different column). |
| XO sauce | Dried scallop, as well as dried shrimp. |
| Squid ink | In black pasta and risotto. |
In the free matrix builder, typing any of these ticks molluscs automatically: Oyster sauce, Mussels, Paella, Moules mariniere.
Cross-contact to think about
- Fryer oil shared with calamari.
- Shellfish cooking water and steamers.
Where your risk assessment finds a risk you cannot control, mark the dish “may contain” on the matrix. Don't use it as a blanket statement: when “may contain” is justified.
On a PPDS label
NOT ENOUGH
Stir-fry sauce
CLEAR
Stir-fry sauce (oyster extract, soy sauce (water, soyabeans, wheat, salt), sugar)
Bought-in sauces bring several allergens at once: copy the whole list.
Make a PPDS label with allergens emphasised automatically →
Mistakes we see on matrices
- Oyster sauce not ticked.
- Squid put in the crustaceans column.
- Scallops forgotten: they are molluscs.
Molluscs: questions from kitchens
Is squid a mollusc or a crustacean?
A mollusc. Squid, octopus and cuttlefish are molluscs; prawns, crab and lobster are crustaceans.
Official sources
- Regulation (EU) No 1169/2011, Annex II — substances or products causing allergies or intolerances — legislation.gov.uk (version applying in Great Britain).
- Allergen guidance for food businesses — Food Standards Agency (GOV.UK), updated 17 July 2026.
- Food allergen labelling and information requirements: technical guidance — Food Standards Agency (GOV.UK), published 23 August 2023, revised March 2025.
- Regulation (EU) No 1169/2011, Article 21 — labelling of allergens — legislation.gov.uk.
All sources opened and checked on 18 September 2026. This page is general information, not legal advice.