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Mustard
Mustard is entry 10 of the fourteen substances Annex II of Regulation (EU) No 1169/2011 makes declarable. IgE-mediated food allergy. Where it hides, which exemptions apply, and what it cross-reacts with.
This is reference information, not a diagnosis and not a treatment plan. A pollen calendar cannot tell you what you are allergic to, and no page can clear a food as safe for you — only the label on the packet in your hand and the clinician who knows your history can do that. Anything beyond mild, short-lived symptoms in the mouth or nose — swelling that affects breathing or swallowing, hives away from the mouth, wheeze, vomiting or faintness — is an emergency question, not a reading question.
What the law says
Annex II, entry 10: “Mustard and products thereof”
That wording carries the whole obligation. The substance must be declared whenever it is used in the making of a food and is still present in the finished product, even in an altered form, and it must be picked out inside the ingredient list by typeset — bold, capitals, italics, underlining or a contrasting colour. There is no legal requirement for a separate allergen box, so the ingredient list is where to look.
Source: Regulation (EU) No 1169/2011, Annex II and Article 21 · checked 2026-09-06
What the reaction actually is
Mustard is a brassica seed, and the relevant allergens are heat-stable storage proteins, so cooking and processing do not remove the risk. It has a reputation for causing reactions to small amounts, which is why an ingredient present in a tablespoon of dressing is treated as seriously as a main ingredient.
Who gets it, and does it last
Mustard allergy is more often diagnosed in France and southern Europe, where consumption is highest, but it occurs everywhere the seed is used. It generally persists.
Where it hides
- Mayonnaise, remoulade and salad dressing
- Sausage, meat marinades and glazes
- Pickles, chutney and piccalilli
- Curry powders and spice mixes
- Barbecue sauce and ketchup varieties
- Some breads and crackers
Mustard runs through the everyday food of this region in the least visible way possible: in the sausage, in the marinade, in the mayonnaise-bound salad and in the pickling brine. A mustard-allergic person eating in the Baltics or the Nordics has to treat prepared sauces as the default risk rather than the exception.
Cross-reactions
Cross-reactions occur within the brassicas — rapeseed, cabbage, broccoli, turnip — although these rarely cause symptoms. Cross-reactivity with mugwort pollen has also been reported, which places mustard loosely alongside the celery and spice group.
The labelling detail
No exemptions. Mustard flour used as an emulsifier or a background note in a sauce is declared and emphasised like any other ingredient, which is what makes the label the practical tool for this allergen.
Exemptions: none. Entry 10 has no carve-outs at all, so there is no processed fraction of it that escapes the label.
Precautionary wording — “may contain”, “made in a factory that also handles” — is a separate matter: it is voluntary, unstandardised and carries no threshold. How strictly to treat it is a clinical decision, not a reading of the label. The labelling explainer sets out the whole frame, including what happens in restaurants and bakeries where there is no pack at all.
What gets misread
Mustard seed, mustard powder and prepared mustard are all mustard. So is the seed in a pickling spice mix. What is not mustard is mustard greens sold as a salad leaf being assumed automatically safe — the same plant, and worth asking a clinician about rather than guessing.
Sources: Regulation (EU) No 1169/2011, Annex II · Commission Implementing Regulation (EU) No 828/2014 (gluten claims) · WHO/IUIS Allergen Nomenclature · season windows from the national aerobiology monitoring programmes of Estonia, Finland, Sweden, Denmark and Norway · cross-reaction patterns paraphrased from the allergy literature and EAACI material · checked 2026-09-06
Frequently asked questions
Is mustard one of the fourteen EU allergens?
Yes, entry 10. The Regulation words it as: Mustard and products thereof. It must be declared and emphasised in the ingredient list of any food sold in the EU that contains it.
Where does mustard hide?
The routine unexpected sources are mayonnaise, remoulade and salad dressing; sausage, meat marinades and glazes; pickles, chutney and piccalilli; curry powders and spice mixes; barbecue sauce and ketchup varieties; some breads and crackers. This is what makes the ingredient list, rather than the name of the dish, the thing to read.
Are there any labelling exemptions for mustard?
No. Entry 10 carries no exemptions, so any mustard-derived ingredient is declarable however small the amount.
What does mustard cross-react with?
Cross-reactions occur within the brassicas — rapeseed, cabbage, broccoli, turnip — although these rarely cause symptoms. Cross-reactivity with mugwort pollen has also been reported, which places mustard loosely alongside the celery and spice group.
Cereals containing gluten
Coeliac disease (autoimmune), wheat allergy (IgE) and non-coeliac wheat sensitivity — three different conditions under one entry.
Crustaceans
IgE-mediated food allergy, mainly to tropomyosin.
Eggs
IgE-mediated food allergy.
Fish
IgE-mediated food allergy, mainly to parvalbumin.
Peanuts
IgE-mediated food allergy — severe storage-protein type, or mild birch-pollen-related type.
Foods by diet and allergen
The food database filtered by written rules. A way to explore, never an allergen clearance.
Keep the log, spot the pattern
When a reaction is hard to pin down, a food and symptom log across weeks is worth more than any single meal you can remember. TempoLife keeps both in one place.