United States
Hong KongThe nine major allergens, and why cross-contact is different
Milk, eggs, fish, crustacean shellfish, tree nuts, peanuts, wheat, soybeans and sesame. Sesame became the ninth on 1 January 2023 under the FASTER Act, so any list of eight predates the change and is out of date.
Nine allergens account for the large majority of serious food allergic reactions in the United States, which is why they carry labeling and training obligations that other foods do not.
The ninth is the one to check your study material against.
| Allergen | Where it hides |
|---|---|
| Milk | Butter in a pan, whey in bread, casein in non-dairy creamer |
| Eggs | Egg wash on pastry, mayonnaise, some pasta, meringue in desserts |
| Fish | Worcestershire and Caesar dressing, both usually anchovy |
| Crustacean shellfish | Stock, bisque, shared fryer oil |
| Tree nuts | Pesto, marzipan, some cooking oils |
| Peanuts | Satay, chilli thickeners, some baked goods |
| Wheat | Soy sauce, thickened sauces, breaded coatings |
| Soybeans | Soy sauce, many oils, texturized protein |
| Sesame | Tahini, hummus, burger buns, spice blends |
The right-hand column is the exam-relevant part. Questions are rarely "is milk an allergen?" - they describe a dish and ask which allergen a customer was not told about.
Cross-contact, not cross-contamination
Two words that look interchangeable and are not.
| Cross-contamination | Cross-contact | |
|---|---|---|
| What moves | A pathogen | An allergen protein |
| Does cooking fix it | Yes, usually | No |
| How much is enough | Depends on the pathogen | A trace |
| Control | Time and temperature, separation | Separation only |
Chips cooked in oil that fried breaded shrimp carry shellfish and wheat protein. Nothing is undercooked, nothing is contaminated in the pathogen sense, and the food is dangerous anyway. That is cross-contact in one sentence.
What a manager is expected to have
- Staff who can answer an allergen question accurately, or who know exactly who to fetch.
- Separate preparation area, utensils and cutting boards for an allergen order.
- Clean hands and fresh gloves before preparing it.
- A route from the customer to someone who knows the actual recipe, including sauces and marinades.
- A dish delivered by someone who knows which plate it is.
Notice what is not on that list: removing the allergen. Picking nuts off a salad does not make it safe, and an answer option offering it is always wrong.
The customer conversation
The correct response to "does this contain sesame?" is not a guess and not reassurance. It is to check, and where nobody can check with confidence, to say so.
That is unsatisfying in a restaurant and it is the answer the exam wants. Two questions in the blueprint sit under developing a food allergen plan, and this is where they live.
Common questions
What are the nine major food allergens?
Milk, eggs, fish, crustacean shellfish, tree nuts, peanuts, wheat, soybeans and sesame. Sesame was added on 1 January 2023 under the FASTER Act.
What is the difference between cross-contact and cross-contamination?
Cross-contamination moves a pathogen and cooking usually destroys it. Cross-contact moves an allergen protein, cooking does not destroy it, and a trace is enough to cause a reaction.
Can you remove an allergen from a dish?
No. Picking nuts off a salad or scraping cheese from a burger leaves protein behind. The dish is remade from clean equipment, and any answer option offering removal is wrong.
Is a shared fryer a problem?
Yes. Oil that has fried breaded shrimp carries shellfish and wheat protein into everything cooked in it afterwards. It is the most common cross-contact scenario on practice exams because it is the most common one in kitchens.
What should staff say if they do not know?
That they will check, and if nobody can confirm with certainty, that they cannot confirm it. Guessing or reassuring the customer is the wrong answer both in the exam and in the restaurant.