The 9 Major Food Allergens You Must Know

Understanding the 9 Major Food Allergens

Food allergies affect approximately 32 million Americans, including 5.6 million children. As a food handler, understanding major food allergens is not just important for passing your certification exam — it can literally save lives. A severe allergic reaction (anaphylaxis) can be fatal within minutes if not treated.

The FDA recognizes 9 major food allergens that must be clearly identified on food labels and that food service workers must be trained to manage:

1. Milk

Milk allergy is one of the most common food allergies, especially in children. It is an immune reaction to the proteins in cow’s milk — different from lactose intolerance, which is a digestive issue. Milk proteins can be found in butter, cheese, cream, yogurt, casein, whey, and many processed foods including baked goods, sauces, and dressings.

2. Eggs

Egg allergy is the second most common allergy in children. Both egg whites and yolks contain allergenic proteins. Eggs are found in many foods including mayonnaise, pasta, baked goods, meringue, and some salad dressings. They are also used as a binding agent and glaze in many recipes.

3. Fish

Fish allergy can develop at any age and is often lifelong. Common allergenic fish include salmon, tuna, cod, bass, and halibut. Fish proteins can become airborne during cooking, potentially triggering reactions even without direct consumption. Fish can also be hidden in Worcestershire sauce, Caesar salad dressing, and some Asian sauces.

4. Shellfish

Shellfish allergy is one of the most common adult-onset food allergies. It includes crustaceans (shrimp, crab, lobster) and mollusks (clams, mussels, oysters, scallops). Shellfish proteins are also found in some sauces, seasonings, and flavorings used in Asian cuisine.

5. Tree Nuts

Tree nut allergy includes almonds, cashews, walnuts, pecans, pistachios, macadamia nuts, Brazil nuts, and hazelnuts, among others. Tree nuts are widely used in baking, cooking, sauces (like pesto), and as garnishes. Tree nut oils may also trigger reactions in some individuals.

6. Peanuts

Peanuts are actually legumes, not true nuts, but they are one of the most dangerous allergens. Peanut allergy is the leading cause of food allergy-related anaphylaxis. Peanuts and peanut derivatives are found in many foods including sauces, baked goods, candy, and some chili recipes.

7. Wheat

Wheat allergy is an immune reaction to wheat proteins. It is different from celiac disease (an autoimmune disorder triggered by gluten) and gluten sensitivity. Wheat is found in bread, pasta, cereal, baked goods, soy sauce, some processed meats, and many other foods.

8. Soybeans

Soy allergy is common in infants and children but often resolves by adulthood. Soy is used extensively in processed foods — soybean oil, soy flour, soy protein, soy lecithin, and soy sauce are just a few examples. It is also found in many Asian dishes, vegetarian products, and processed meats.

9. Sesame

Sesame became the 9th major allergen when the FASTER Act (Food Allergy Safety, Treatment, Education, and Research Act) took effect on January 1, 2023. Sesame is found in hummus, tahini, bread, bagels, crackers, sushi, and many Middle Eastern and Asian dishes. Sesame oil and sesame seeds are increasingly common in American cuisine.

Preventing Allergic Reactions in Food Service

As a food handler, you play a critical role in preventing allergic reactions:

• Communicate: Always take allergy requests seriously. Never dismiss or minimize a customer’s allergy.
• Prevent cross-contact: Use separate cutting boards, utensils, and cooking surfaces for allergen-free meals.
• Read labels: Check ingredient labels on all packaged foods. Allergens can be hidden in unexpected products.
• Clean thoroughly: Wash hands and sanitize surfaces between handling allergenic and non-allergenic foods.
• Know your menu: Be familiar with which dishes contain major allergens so you can answer customer questions accurately.

Food allergen questions typically make up 3–5 questions on the food handler exam. Our free practice test includes allergen-specific questions to ensure you are fully prepared.