Key Takeaways

  • Big Nine allergens: milk, eggs, fish, shellfish, tree nuts, peanuts, wheat, soybeans, sesame
  • Sesame was added as the 9th allergen on January 1, 2023
  • Food allergies can cause life-threatening anaphylaxis
  • Many allergens are hidden in unexpected foods
  • Allergy (immune response) is different from intolerance (digestive response)
Last updated: January 2026

4.1 The Big Nine Allergens

Food allergies can cause severe reactions, including anaphylaxis, which can be fatal. As a food handler, you must understand allergens and how to prevent cross-contact.

What Is a Food Allergy?

A food allergy is an immune system response to a specific protein in food. Unlike food intolerance (which causes discomfort), a true food allergy can be life-threatening.

Symptoms of allergic reaction:

  • Hives, rash, or itching
  • Swelling of lips, tongue, throat
  • Difficulty breathing, wheezing
  • Nausea, vomiting, diarrhea
  • Dizziness or fainting
  • Anaphylaxis (severe, life-threatening)

The Big Nine Allergens

As of January 1, 2023 (FASTER Act), nine allergens must be clearly labeled:

AllergenCommon Sources
1. MilkButter, cheese, cream, yogurt, whey, casein
2. EggsMayonnaise, meringue, some pasta, baked goods
3. FishAnchovies, bass, cod, salmon, sauces (Worcestershire)
4. Crustacean ShellfishCrab, lobster, shrimp, crawfish
5. Tree NutsAlmonds, cashews, walnuts, pecans, pine nuts
6. PeanutsPeanut butter, peanut oil, many sauces
7. WheatBread, pasta, crackers, flour, soy sauce
8. SoybeansTofu, soy sauce, miso, many processed foods
9. SesameSesame seeds, tahini, hummus, some breads

For the Exam: Sesame was added as the 9th allergen on January 1, 2023. Previous versions only had the "Big Eight."

Hidden Allergens

Many allergens are found in unexpected foods:

AllergenHidden In
MilkCaesar dressing, chocolate, deli meats
EggsSalad dressings, some pastas, fried foods (batter)
PeanutsChili, egg rolls, some sauces
WheatSoy sauce, beer, processed meats
SoyVegetable broth, canned tuna, cereal
FishCaesar dressing, Worcestershire sauce

Allergy vs. Intolerance

AllergyIntolerance
Immune system responseDigestive system response
Can be life-threateningCauses discomfort, not usually dangerous
Even tiny amounts triggerUsually dose-dependent
Examples: Peanut, shellfish allergiesExamples: Lactose intolerance, gluten sensitivity
Test Your Knowledge

How many major food allergens are required to be labeled under the FASTER Act (2023)?

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Test Your Knowledge

Which allergen was MOST RECENTLY added to the major allergens list?

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Test Your Knowledge

What is the main difference between a food allergy and food intolerance?

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D