The Major Food Allergens: What Every Label Reader Needs to Know

Food allergies affect an estimated 1 in 10 people worldwide. Yet wherever you live, navigating a grocery store can still feel like defusing a bomb. Staying safe starts with knowing the major allergens regulators require to be declared on packaged food — and those lists differ depending on where your food comes from.

The lists differ by region

Most countries mandate clear labelling for a core set of allergens, but the exact list depends on where a product was made:

• United States declares 9: milk, eggs, fish, crustacean shellfish, tree nuts, peanuts, wheat, soybeans, and sesame (added in 2023).
• European Union & UK declare 14 — the nine above plus celery, mustard, sulphites, lupin, and molluscs.
• Canada, Australia, and others maintain their own priority-allergen lists that broadly overlap with these.

This is exactly why a product that looks clearly labelled in one country can be confusing when it's imported from another.

The most common culprits

Whichever list applies to you, these are the allergens that turn up most often — and the unexpected places they hide:

1. Milk — In obvious dairy, but also many breads, cereals, and processed meats.
2. Eggs — A binding agent in countless baked goods, pasta, and sauces.
3. Fish — Includes bass, flounder, cod, and more. Fish sauce can be a hidden source.
4. Shellfish — Shrimp, crab, lobster. Cross-contact risk is high in seafood kitchens.
5. Tree nuts — Almonds, cashews, walnuts, pecans. Each is considered a separate allergen.
6. Peanuts — Technically a legume, but one of the most common and severe allergens.
7. Wheat & gluten cereals — Behind both wheat allergy and gluten-related concerns.
8. Soybeans — Found in edamame, tofu, miso, and many packaged snacks.
9. Sesame, celery, mustard, sulphites, lupin & molluscs — Required on EU/UK labels, and worth watching anywhere.

Why labels still fail people

Even with mandatory labelling, allergens hide in unexpected places:

• "Natural flavours" can sometimes contain derivatives of allergens.
• Cross-contact during manufacturing means a product made on shared equipment may not always be clearly labelled.
• Imported products may use different naming conventions or follow a different country's rules.

How Purelyst helps

Purelyst checks barcodes against Open Food Facts — a global, community-maintained food database — and for anything not listed, label mode lets you photograph the ingredient list so AI can read it for you, in most major languages. Either way, Purelyst:

• Flags declared allergens from the label
• Warns about "may contain" cross-contact statements
• Matches against your exact profile — not just one country's standard list

And with Safe Circles, every member's profile is checked simultaneously. You'll know in one tap whether the snack is safe for everyone at the table.

Stay curious, stay safe.