The Big 9 Food Allergens: A Comprehensive Guide for Restaurant Operators

Understanding and managing food allergens is essential for every food service operation. For years, the Big 8 allergens — milk, eggs, fish, shellfish, tree nuts, peanuts, wheat, and soy — were recognized as the most common causes of food allergies in the U.S. However, as of January 1, 2023, sesame has been officially added as the 9th major food allergen under the Food Allergy Safety, Treatment, Education, and Research (FASTER) Act, requiring clear labeling on packaged foods.

These nine allergens account for 90% of all food allergic reactions in the U.S., with reactions ranging from mild discomfort to life-threatening anaphylaxis. For restaurant operators, proper allergen management is not just about compliance—it’s about ensuring customer safety, trust, and inclusivity in dining experiences.

Overview of the Big 9

The Food Allergen Labeling and Consumer Protection Act (FALCPA) identifies eight major food allergens that require special attention in food service operations:

Milk

What it includes: Dairy products such as milk, butter, cheese, yogurt, cream, and ingredients like casein, whey, and lactose.

Where it’s commonly found:

• Sauces and soups (e.g., Alfredo sauce, béchamel, chowders)

• Baked goods (e.g., bread, cakes, cookies)

• Processed foods (e.g., margarine, deli meats, protein powders)

Cross-contamination risks:

• Shared utensils, grills, and fryers used for both dairy and non-dairy items.

• Steam wands on espresso machines used for both dairy and non-dairy milk.

Allergy considerations for food service:

• Offer dairy-free alternatives like almond, oat, or soy milk.

• Clearly label menu items containing milk or dairy-based ingredients.

• Train staff on proper cleaning methods to prevent cross-contact.

Eggs

What It Includes: Both egg whites and yolks can trigger allergic reactions, as well as egg-derived ingredients like albumin, lysozyme, and lecithin (when sourced from eggs).

Where it’s commonly found:

• Obvious sources: Scrambled eggs, omelets, custards, and meringues.

• Hidden sources: Egg wash on bread, mayonnaise, aioli, and some salad dressings.

• Unexpected sources: Battered and fried foods, pasta, some coffee drinks (e.g., traditional egg-based foams).

Cross-contamination risks:

• Baking surfaces, whisks, and mixers used for both egg-based and egg-free recipes.

• Shared fryers where egg-battered foods are cooked.

• Grills where scrambled eggs and other food are cooked.

Allergy considerations for food service:

• Offer egg-free alternatives for baked goods and dressings (e.g., plant-based mayo).

• Use dedicated utensils and cooking surfaces for egg-free menu items.

• Label egg-containing dishes clearly and inform staff about hidden sources.

Fish

What it includes: Each species of fish (e.g., salmon, cod, tuna, haddock) is treated as a separate allergen, but cross-reactivity between species is common.

Where it’s commonly found:

• Obvious sources: Grilled, baked, or fried fish dishes (e.g., fish tacos, fish and chips)

• Hidden sources:

  • Fish sauce (commonly used in Asian cuisine)

  • Worcestershire sauce (contains anchovies)

  • Caesar dressing (often contains anchovies)

Cross-contamination risks:

• Shared grills or pans used for both fish and non-fish items.

• Fryers used to cook both fish and other fried menu items.

• Serving utensils or cutting boards that have not been properly cleaned.

Allergy considerations for food service:

• Use dedicated cooking equipment (grills, pans, fryers) for non-fish items.

• Clearly label menu items that contain fish or fish-based ingredients.

• Educate staff on identifying less obvious sources of fish, such as sauces or dressings.

Shellfish

What it includes: Shellfish are divided into two groups — crustaceans (shrimp, crab, lobster) and mollusks (clams, mussels, oysters). Crustacean allergies are typically more severe and more likely to cause anaphylaxis.

Where it’s commonly found:

• Obvious sources: Shrimp cocktails, crab cakes, seafood soups, and fried calamari

• Hidden sources:

  • Sauces and broths (e.g., seafood stock, fish sauce)

  • Some sushi rolls and imitation crab (surimi)

  • Fried foods cooked in shared oil with shellfish

Cross-contamination risks:

• Shared fryers, grills, and utensils used for both shellfish and non-shellfish dishes.

• Steam and airborne particles in kitchens where shellfish is prepared.

• Cooking oils that have been used to fry shrimp, crab, or other shellfish.

Allergy considerations for food service:

• Use separate cooking oil, utensils, and prep areas for shellfish-free meals.

• Label shellfish-containing dishes clearly on menus and ingredient lists.

• Train staff to recognize and prevent cross-contact, especially in frying and grilling.

Tree nuts

What it includes: Tree nuts include almonds, walnuts, pecans, cashews, pistachios, hazelnuts, and more. Each type is a distinct allergen, but cross-reactivity between different nuts is common.

Where it’s commonly found:

• Obvious sources: Nut butter, trail mixes, granola, and baked goods

• Hidden sources:

  • Sauces (e.g., pesto made with pine nuts)

  • Salad dressings (e.g., walnut oil-based vinaigrettes)

  • Desserts (e.g., marzipan, pralines, and some chocolates)

Cross-contamination risks:

• Shared cutting boards, knives, and baking equipment used for nut-containing and nut-free foods.

• Bulk bins where different types of nuts and seeds are stored together.

• Oils or flavor extracts derived from nuts, even in non-nut products.

Allergy considerations for food service:

• Clearly label dishes that contain tree nuts or nut-derived ingredients.

• Store nuts separately from other ingredients to prevent cross-contact.

• Train staff on recognizing tree nut-containing items, including sauces and dressings.

Peanuts

What it includes: Though peanuts are legumes, not tree nuts, they are one of the most common and potentially severe food allergens, often causing life-threatening reactions.

Where it’s commonly found:

• Obvious sources: Peanut butter, peanut oil, and peanut-based snacks

• Hidden sources:

  • Asian cuisine (e.g., satay sauce, pad thai, peanut-based curries)

  • Baked goods (e.g., cookies, brownies, granola bars)

  • Sauces and dressings (e.g., peanut-based salad dressings, mole sauce)

Cross-contamination risks:

• Shared fryers, prep areas, and utensils used for peanut and non-peanut foods.

• Peanut residue in bulk bins, candy mixes, and processed snack foods.

• Airborne peanut particles in kitchens where peanuts are frequently used.

Allergy considerations for food service:

• Offer peanut-free alternatives, such as sunflower butter or almond butter.

• Store peanuts separately from other ingredients and use dedicated equipment.

• Clearly label peanut-containing dishes and train staff on allergy safety protocols.

Soybeans

What it includes: Soy is a common ingredient in processed foods, Asian cuisine, and vegetarian alternatives. It appears in multiple forms, including soy protein, soy lecithin, and soybean oil.

Where it’s commonly found:

• Obvious sources: Tofu, tempeh, soy milk, edamame

• Hidden sources:

  • Sauces (e.g., soy sauce, teriyaki, hoisin sauce)

  • Processed foods (e.g., protein bars, veggie burgers, deli meats)

  • Baking ingredients (e.g., soy flour, soy lecithin in chocolate and bread)

Cross-contamination risks:

• Shared cooking oil in deep fryers, as soybean oil is commonly used.

• Marinades, broths, and sauces that contain soy as a base ingredient.

• Processing equipment used for both soy and non-soy products.

Allergy considerations for food service:

• Provide soy-free alternatives, such as coconut aminos instead of soy sauce.

• Label soy-containing menu items clearly, including processed foods with soy derivatives.

• Train staff on identifying soy in ingredient lists and preventing cross-contact.

Wheat

What it includes: Wheat is a common ingredient in many foods, including baked goods, pasta, and processed products. It can appear in various forms, such as wheat flour, semolina, durum, and modified food starch.

Where it’s commonly found:

• Obvious sources: Bread, pasta, crackers, baked goods

• Hidden sources:

  • Soy sauce, beer, and some condiments

  • Spice blends and seasonings that use wheat as an anti-caking agent

  • Soups, sauces, and gravies thickened with wheat-based roux or starch

Cross-contamination risks:

• Shared baking surfaces, toasters, and utensils used for wheat-containing and gluten-free foods.

• Airborne flour in bakeries and kitchens where wheat-based ingredients are processed.

• Fryers used for both wheat-battered and non-wheat foods.

Allergy considerations for food service:

• Offer wheat-free or gluten-free alternatives, such as tamari instead of soy sauce.

• Store wheat-containing products separately from gluten-free ingredients.

• Train staff on preventing cross-contact, especially in baking and frying areas.

Sesame

What it includes: Sesame is a widely used ingredient found in whole seeds, sesame oil, tahini, and sesame-based seasonings. It can appear in foods in visible or ground forms and is sometimes labeled under alternative names, such as "benne" or "sesamol."

Where it’s commonly found:

• Obvious sources:

• Sesame seeds, tahini, hummus, sesame oil

• Breads, bagels, crackers, and burger buns

• Asian cuisine, including sushi, stir-fries, and tempura

• Hidden sources:

• Processed foods like granola, snack bars, and flavored rice mixes

• Spice blends, marinades, and salad dressings

• Deli meats and vegetarian meat substitutes that use sesame for flavoring or texture

• Certain baked goods that may be dusted with sesame or contain traces from shared equipment

Cross-contamination risks:

• Shared bakery equipment, such as bread slicers and rolling pins, where sesame seeds can stick to surfaces.

• Fryers and grills used for foods coated with sesame or cooked in sesame oil.

• Bulk food bins and spice containers where sesame-based products are stored alongside non-sesame items.

Allergy considerations for food service:

• Clearly label sesame-containing foods and disclose possible cross-contact risks.

• Use separate utensils and preparation areas for sesame-free dishes.

• Offer sesame-free alternatives, such as sunflower seed butter instead of tahini.

• Educate staff on reading ingredient labels carefully, as sesame may be listed under different names.

Kitchen management strategies

Dr. Stephanie Leonard is a food allergy specialist at Rady Children’s Hospital-San Diego — and she also has a life-threatening allergy to peanuts. “Every time I put food in my mouth, I’m reminded of my food allergy,” she shared. “Most restaurants have good intentions, but there’s always the possibility of a misunderstanding or cross-contact with a food allergen … Both the customer and the restaurant staff have to communicate clearly and be prepared.”

Her personal experience highlights the risks of cross-contact in restaurant kitchens. A pesto dish she once ordered didn’t contain peanuts, but the pine nuts had been ground in the same equipment used for peanuts, exposing her to trace amounts of the allergen. Even a small amount was enough to put her at risk for anaphylaxis, reinforcing the importance of strict kitchen protocols to prevent cross-contact.

This incident underscores how easily cross-contact can happen in a busy kitchen. That’s why a strong allergen management system must start with strict protocols for food storage, preparation, cooking, and service to prevent cross-contamination and protect customers.

Storage

Proper storage of allergen-containing ingredients is essential to prevent cross-contact, maintain food safety, and ensure compliance with allergen management protocols. Follow these best practices:

• Separate storage areas: Designate specific spaces for allergen-containing ingredients.

• Prevent cross-contact: Store allergens away from non-allergen foods to avoid spills and airborne contamination.

• Use sealed containers: Keep allergen-containing items in airtight containers and label them clearly.

• Shelf placement: Place allergen-containing bulk ingredients on lower shelves to prevent drips onto allergen-free foods.

Preparation

Proper preparation techniques are crucial for minimizing cross-contact and ensuring allergen-free meals are handled safely. Implement these key practices:

• Dedicated prep areas: Use separate prep areas and equipment for allergen-free dishes.

• Color-coded equipment: Assign color-coded cutting boards, utensils, and containers to prevent mix-ups.

• Sanitation protocols: Thoroughly clean and sanitize surfaces, appliances, and cookware between uses.

• Staff training: Educate kitchen staff on allergen risks and proper food handling procedures.

Cooking

Proper cooking procedures help prevent cross-contact and ensure allergen-free meals remain safe for consumption. Follow these procedures:

• Separate cooking surfaces: Use separate grills, fryers, pans, and cooking surfaces for allergen-free meals.

• Avoid shared oil and water: Never cook allergen-free foods in the same oil or water used for allergen-containing items.

• Order prioritization: Cook allergen-free meals first or in a designated area to minimize exposure.

• Clean utensils: Wash and sanitize cooking tools before handling allergen-free dishes.

Service

Maintaining allergen safety continues all the way through service, requiring clear communication and careful handling of allergen-free meals. Follow these essential guidelines:

• Clear communication: Establish protocols between front-of-house and kitchen staff to ensure allergen safety.

• Distinctive plating: Use designated plates, markers, or labels for allergen-free dishes.

• Server training: Teach staff how to accurately communicate allergen information to customers and verify ingredient details with the kitchen.

• Clarifying questions: Encourage staff to ask clarifying questions when customers mention allergies to ensure proper handling.

Staff training requirements

All staff members should receive comprehensive allergen training to guarantee food safety and minimize the risk of allergic reactions. Proper training equips both kitchen and front-of-house staff with the knowledge and skills needed to handle allergens safely, prevent cross-contact, and respond to emergencies effectively.

Kitchen staff

Kitchen staff are the first line of defense in allergen management, responsible for maintaining strict food safety practices and preventing cross-contact at every stage of meal preparation. Implement these procedures to ensure a safe dining experience:

• Handling and storage procedures: Store allergens separately and follow designated handling protocols to prevent mix-ups.

• Cross-contamination prevention: Use separate equipment, utensils, and prep areas for allergen-free meals.

• Cleaning and sanitization: Follow strict cleaning protocols to remove allergen residues from surfaces and tools.

• Recipe knowledge and modifications: Understand which menu items contain allergens and how to safely modify dishes when necessary.

• Emergency response procedures: Recognize the signs of an allergic reaction and know how to respond, including when to call for medical assistance.

Proper food handling is essential to prevent cross-contact, especially for customers with severe allergies. Even small traces of an allergen left on surfaces or utensils can pose a serious risk. Consider this example:

Incorrect Handling: A cook prepares a sandwich on a cutting board dusted with flour, then uses the same board to assemble a salad for a customer with a wheat allergy, without properly cleaning it.

Correct Handling: A cook follows allergen-safe procedures by using a separate, designated cutting board and sanitized knife to prevent cross-contact with wheat.

Service staff

Service staff play a crucial role in allergen safety, acting as the link between customers and the kitchen to ensure accurate communication and proper handling of allergen-free meals. Maintain a safe dining experience with:

• Menu knowledge: Be familiar with all menu items, including hidden allergens in sauces, dressings, and processed ingredients.

• Communication protocols: Clearly communicate allergen concerns to kitchen staff and verify ingredient details when needed.

• Proper service procedures: Use designated plates, tags, or markers to identify allergen-free dishes and prevent cross-contact during service.

• Customer interaction: Ask clarifying questions when a guest mentions an allergy and provide accurate, confident information about allergen risks.

• Emergency response procedures: Know how to recognize and respond to allergic reactions, including how to assist a guest in distress and when to seek medical help.

Even seemingly safe menu items can contain hidden allergens, making it essential for servers to be aware of potential risks. Break down menu items to notice where allergens could be hiding:

Example: Caesar Salad

• Dressing: Often contains anchovies (fish) and eggs.

• Croutons: May contain wheat and dairy (butter or cheese coatings).

• Toppings: Some versions include walnuts (tree nuts).

Management

Management is responsible for developing, enforcing, and continuously improving allergen safety protocols to protect both customers and staff. These key responsibilities ensure compliance and maintain a safe food service environment:

• Allergen program development and maintenance: Establish and oversee allergen safety protocols to ensure compliance with food safety regulations.

• Staff training oversight: Ensure all employees receive initial and ongoing allergen training and conduct refresher sessions as needed.

• Emergency response coordination: Develop and implement emergency action plans for allergic reactions and train staff on response procedures.

• Supplier verification procedures: Vet suppliers to confirm ingredient transparency and monitor for formulation changes that could introduce allergens.

• Documentation and record-keeping: Maintain allergen training records, updated ingredient lists, and reports on any allergen-related incidents.

For example, a restaurant orders "nut-free" bread from a supplier, but a recipe change adds almond flour without notice. Thanks to the manager’s routine supplier check, the issue is caught before serving customers with nut allergies, highlighting the importance of supplier verification and regular ingredient reviews.

Documentation and record keeping

Maintaining accurate and up-to-date records is essential for ensuring compliance, tracking allergen safety measures, and responding to incidents effectively. Proper documentation helps food service operations identify risks, improve procedures, and protect customers with food allergies. Keep detailed records of:

• Ingredient lists and supplier information: Keep detailed records of all ingredients used in menu items, including supplier details and any changes to ingredient formulations.

• Recipe specifications including all sub-ingredients: Document full recipes with precise ingredient breakdowns, including any hidden allergens found in sauces, spice blends, and processed ingredients.

• Staff training completion and dates: Maintain records of all allergen training sessions, including dates, employee names, and certification details to ensure compliance and accountability.

• Cleaning and sanitization procedures: Track cleaning protocols for allergen-free prep areas, utensils, and equipment, documenting the frequency and any corrective actions taken.

• Incident reports and corrective actions: Record all allergen-related incidents, outlining what occurred, how staff responded, and what measures were implemented to prevent future occurrences.

• Customer feedback and complaints: Document customer concerns regarding allergen safety, ensuring all feedback is reviewed and used to improve allergen management procedures.

Emergency response planning

A proactive approach to allergen safety begins with prevention, ensuring that risks are minimized before an incident occurs. Establishing clear protocols and regular oversight helps prevent accidental allergen exposure in food service operations.

Prevention

A strong allergen prevention strategy relies on clear protocols, staff training, and strict food safety measures to minimize cross-contact risks. Regular monitoring and updates ensure continued compliance and reinforce best practices. Key practices include:

• Clear allergen identification systems: Implement standardized labeling and menu notations to clearly identify allergen-containing items for both staff and customers.

• Staff training in prevention: Provide ongoing training to ensure all employees understand allergen risks, cross-contact prevention, and proper handling procedures.

• Regular audit of procedures: Conduct routine evaluations of allergen management protocols to identify gaps and reinforce best practices.

• Updated ingredient lists: Maintain current records of all menu ingredients and sub-ingredients, ensuring staff is aware of any formulation changes that may introduce allergens.

Response

Despite strong prevention measures, accidental allergen exposure can still occur. A well-defined emergency response plan ensures that staff can act quickly and effectively to protect customers in the event of an allergic reaction. Key steps include clarifying:

• Staff roles in emergencies: Clearly define responsibilities so employees know who should assist the affected customer, who should call emergency services, and who should document the incident.

• Location of emergency equipment: Ensure all staff know the location of emergency supplies, such as epinephrine auto-injectors (if available), first-aid kits, and emergency contact lists.

• Communication protocols: Train staff on how to communicate effectively during an emergency, including alerting management, coordinating with medical responders, and informing other team members without causing panic.

• Documentation procedures: Maintain detailed records of all allergen-related incidents, including what happened, how staff responded, and any follow-up actions taken to improve future safety protocols.

For example, a customer informs their server of a shellfish allergy, but despite the warning, their dish is mistakenly prepared with a sauce containing shrimp paste. The customer has a severe reaction, but because the staff is trained, they quickly administer first aid, call 911, and document the incident. This underscores the importance of clear communication and a well-prepared emergency response plan.

Recovery

Following an allergen-related incident, a structured recovery process is essential to identify the cause, implement corrective measures, and strengthen future prevention efforts. A thorough response ensures continuous improvement in allergen management and reinforces customer trust. Effective incident recovery includes:

• Incident investigation procedures: Conduct a detailed review of the incident, including staff interviews, food preparation analysis, and identification of any protocol failures.

• Corrective action implementation: Address identified weaknesses by modifying procedures, reinforcing best practices, or introducing additional safety measures.

• Staff retraining as needed: Provide targeted retraining for involved employees and, if necessary, conduct company-wide refreshers to reinforce allergen safety protocols.

• Policy and procedure updates: Revise allergen management policies based on findings from the investigation, ensuring updated guidelines are effectively communicated and implemented.

Legal compliance

With 33 million Americans affected by food allergies, accurate allergen labeling and proper staff training are not just best practices — they are legal and ethical necessities. Restaurants and food service operations must follow disclosure, training, and documentation requirements to ensure transparency and safety. 

Disclosure Requirements

Proper allergen disclosure ensures that customers can make informed dining decisions and that staff can accurately communicate allergen risks. Responsibilities include:

• Clear identification of major allergens: Label menus, ingredient lists, and packaging to indicate the presence of allergens in compliance with food safety regulations.

• Staff knowledge of ingredients: Ensure employees are familiar with all menu items, including hidden allergens in sauces, marinades, and processed foods.

• Proper response to allergen inquiries: Train staff to confidently and accurately answer customer questions about allergens and cross-contact risks.

• Documentation of procedures: Maintain written records of allergen handling policies, ingredient sources, and staff training to demonstrate compliance with food safety laws.

For example, a restaurant lists a burger as "vegan," but the bun contains whey, a milk derivative. Without clear allergen labeling, a customer with a dairy allergy may assume the meal is safe and unknowingly consume the allergen, creating the possibility of an allergic reaction. This example highlights the importance of accurate menu descriptions and clear allergen disclosure to prevent dangerous mistakes.

Liability considerations

Food service establishments must take reasonable precautions to minimize allergen risks, provide clear warnings, document incidents, and maintain proper insurance coverage to protect both customers and the business. Allergen management includes:

• Duty of care to customers: Establish and enforce strict allergen management protocols to prevent cross-contact and protect guests with food allergies.

• Proper warning requirements: Clearly identify major allergens on menus, signage, and ingredient labels to ensure customers can make informed choices.

• Documentation of incidents: Maintain detailed records of allergen-related incidents, including staff response, corrective actions, and follow-up measures.

• Insurance coverage review: Regularly assess liability insurance policies to confirm adequate coverage for allergen-related claims and legal protections.

By implementing strong allergen management practices, food service operators can minimize legal risks, enhance food safety, and build customer trust.

Frequently Asked Questions

How do we handle customer requests for allergen information? 

Train staff to take all allergen requests seriously. Have current ingredient lists readily available and ensure clear communication between front-of-house and kitchen staff. When in doubt, err on the side of caution.

What cleaning procedures are necessary to use between preparing allergenic and non-allergenic foods? 

Complete cleaning and sanitization of all surfaces, equipment, and utensils is required. This includes changing gloves, using fresh cutting boards, and ensuring no cross-contamination from clothing or other sources.

How do we modify recipes for allergen-free requests? 

Have standardized procedures for common modifications. Ensure all ingredients, including secondary ingredients in sauces and seasonings, are verified. Use separate preparation areas and equipment.

What documentation should we maintain regarding allergens? 

Keep detailed records of ingredients, supplier information, staff training, cleaning procedures, and any allergen-related incidents. Regularly update these records and make them easily accessible to staff.

How do we handle shared equipment like fryers and grills? 

Ideally, maintain separate equipment for allergen-free preparation. If not possible, implement strict cleaning procedures and inform customers of potential cross-contamination risks.

What training should new staff receive regarding allergens? 

All new staff should receive comprehensive training on allergen identification, handling procedures, cross-contamination prevention, and emergency response before working independently.

Moving forward

Managing food allergens effectively requires constant vigilance and a comprehensive system of policies and procedures. Success depends on thorough staff training, clear communication protocols, and consistent implementation of safety measures. Regular review and updates of procedures, combined with ongoing staff training, help ensure customer safety and maintain compliance with regulations.

Remember that allergen management is not just about following rules — it's about protecting customers' health and maintaining their trust in your establishment. A reputation for careful allergen handling can become a significant business advantage, while a single serious incident can have devastating consequences for both customers and the business.