How many major food allergens does U.S. federal law recognize?

Nine, as of January 1, 2023. The original eight under FALCPA (2004) were milk, eggs, fish, crustacean shellfish, tree nuts, peanuts, wheat, and soybeans. The FASTER Act of 2021 added sesame as the ninth major food allergen effective January 1, 2023.

Are mollusks (oysters, clams, mussels, scallops) on the federal major-allergen list?

No. The federal list of nine major food allergens covers crustacean shellfish (crab, lobster, shrimp, crawfish) but not mollusks. However, mollusk allergies are real and serious, and many restaurants treat mollusks as a major allergen voluntarily.

Does cooking destroy food allergens?

No. Allergenic proteins are heat-stable. Cooking, frying, or baking will not eliminate the risk of an allergic reaction. The only effective control is preventing the allergen from contacting the food in the first place — through ingredient awareness, dedicated equipment, proper cleaning, and trained staff.

What does the 2022 FDA Food Code require for allergen communication?

Two things. First, the Person in Charge must demonstrate knowledge of the major food allergens and ensure food employees are trained in food allergy awareness (§2-102.11 and §2-103.11(O)). Second, for unpackaged foods served or sold to consumers, §3-602.12 requires written notification of major allergens in jurisdictions that have adopted the 2022 Food Code provision — for example, menu indicators, deli case signage, or printed allergen guides. Verbal-only disclosure is not sufficient in those jurisdictions.

Is sanitizer enough to remove allergen residue from a surface?

No. Sanitizer reduces microbial load; it does not remove allergenic proteins. Allergen-contaminated surfaces must be physically cleaned with hot soapy water, rinsed, and then sanitized. Wiping a surface with a sanitized cloth — even an EPA-registered sanitizer — does not eliminate allergen residue.

Food Allergen Cross-Contact Prevention — The 9 Major Allergens and FDA Food Code Requirements

TL;DR

U.S. federal law recognizes nine major food allergens: milk, eggs, fish, crustacean shellfish, tree nuts, peanuts, wheat, soybeans, and sesame — sesame was added by the FASTER Act of 2021 and became the ninth major food allergen on January 1, 2023. Cross-contact is the unintentional transfer of an allergen from one food, surface, or utensil to another food that wasn't supposed to contain it; it is not the same as cross-contamination (the transfer of pathogens). The 2022 FDA Food Code is a model code; provisions become enforceable when adopted by a state, local, tribal, or territorial jurisdiction. The 2022 Code requires the Person in Charge to demonstrate knowledge of the nine major food allergens (§2-102.11) and to ensure food employees are trained in food allergy awareness (§2-103.11(O)). For unpackaged foods served or sold to consumers, the 2022 Code added a written major-allergen notification provision (§3-602.12); in jurisdictions that have adopted that provision, verbal-only disclosure is not enough. Prevention rests on four pillars: ingredient awareness, dedicated/cleaned equipment, accurate communication from order to plate, and trained staff.

Cross-Contact Is Not Cross-Contamination

These two terms get used interchangeably in everyday kitchen talk, but on a food handler exam — and in a Food Code-based health inspection — they are not the same thing. Cross-contamination refers to the transfer of harmful microorganisms (pathogens) from one food, surface, or person to another — for example, juices from raw chicken contaminating a salad. Cross-contact refers to the unintentional incorporation of a food allergen into a food that was not supposed to contain it. The FDA defines allergen cross-contact in its Current Good Manufacturing Practice regulation as "the unintentional incorporation of a food allergen into a food."

The distinction matters because cross-contamination is killed by proper cooking, while allergen cross-contact is not. Cooking a sesame-containing oil at high heat does not destroy the allergenic proteins. Wiping a peanut-residue knife with a paper towel does not eliminate the protein from the blade. Allergen control requires physical removal — proper cleaning with soap and water, dedicated equipment, or full separation.

The Nine Major Food Allergens

Federal law identifies a specific list of "major food allergens." Until January 1, 2023, the list contained eight items, set by the Food Allergen Labeling and Consumer Protection Act of 2004 (FALCPA). On April 23, 2021, the Food Allergy Safety, Treatment, Education, and Research (FASTER) Act was signed into law, adding sesame as the ninth major food allergen effective January 1, 2023. The nine major food allergens are:

Milk — including butter, cheese, whey, casein, and lactose-containing ingredients
Eggs — both whites and yolks; includes albumin and egg-derived emulsifiers
Fish — bass, flounder, cod, tuna, salmon, and other finned fish
Crustacean shellfish — crab, lobster, shrimp, crawfish; mollusks (clams, oysters, mussels, scallops) are not on the federal list but are common allergens
Tree nuts — almonds, walnuts, pecans, pistachios, cashews, hazelnuts, Brazil nuts, macadamia nuts, pine nuts
Peanuts — a legume, not a tree nut, but listed separately because of severe reactions
Wheat — including spelt, durum, kamut, semolina, and wheat-derived ingredients like gluten
Soybeans — including soy sauce, edamame, tofu, miso, and many emulsifiers
Sesame — added January 1, 2023; includes sesame seeds, sesame oil, tahini, and any sesame-derived ingredients

These nine allergens account for the majority of severe food allergic reactions in the United States. Symptoms range from mild (hives, itching, mild swelling) to severe (anaphylaxis — a life-threatening systemic reaction that can cause throat closure, blood-pressure collapse, and death within minutes if untreated).

FDA Food Code Requirements for Allergens

The 2022 FDA Food Code — the model code most U.S. jurisdictions adopt for retail food establishments — has specific allergen requirements that food employees and Persons in Charge must know:

§2-102.11 Demonstration of knowledge. The Person in Charge must be able to demonstrate, on request, knowledge of foodborne disease prevention, HACCP principles, and Food Code requirements — which includes describing the foods identified as major food allergens and the symptoms of a food allergy reaction.
§2-103.11(O) Duties of the Person in Charge. The PIC must ensure that food employees are properly trained in food allergy awareness as it relates to their assigned duties.
§3-602.11 Food Labels. Packaged food sold in a retail food establishment must declare the major food allergens it contains on the label.
§3-602.12 Other Forms of Information. For unpackaged foods served or sold to consumers within a retail food establishment, the 2022 Food Code added a requirement that written notification of major food allergens be provided to consumers. This is one of the most significant 2022 Code changes — in jurisdictions that have adopted §3-602.12, verbal-only allergen communication is no longer enough.

Prevention Practices

Allergen cross-contact prevention rests on four operational pillars:

1. Ingredient Awareness

Know what is in every dish and every product you serve. Read ingredient lists on packaged products — major food allergens must be declared on labels under FALCPA and the FASTER Act. Recognize hidden allergens: soy lecithin in many baked goods (soybean), casein in non-dairy creamers (milk), sesame oil in stir-fries and dressings, anchovies in Caesar dressing and Worcestershire sauce (fish). If a customer asks about an ingredient and you are not sure, ask the kitchen — never guess.

2. Dedicated or Properly Cleaned Equipment

Allergen residue on shared equipment is one of the most common cross-contact pathways. Best practice is dedicated equipment for high-risk allergen prep — separate fryers for peanut and non-peanut, dedicated cutting boards for known-allergen menu items, color-coded utensils. When dedication isn't feasible, equipment must be thoroughly washed with hot soapy water, rinsed, and sanitized between uses — wiping with a cloth is not enough. Proper cleaning and sanitizing removes allergenic proteins; sanitizing alone does not.

3. Communication from Order to Plate

A customer's allergen disclosure must travel from the server to the kitchen to the expediter to the runner without being lost or garbled. The standard practice in modern restaurants is a written ticket flag (a sticker or POS flag) that physically accompanies the order, combined with a verbal handoff at the pass. When in doubt, the kitchen should remake the dish on dedicated, freshly cleaned equipment rather than scrape allergen residue off a plated portion.

4. Trained Staff

Every food employee — not just managers — must understand what the major allergens are, what cross-contact looks like, and how to respond to a customer's allergen request. Under the 2022 Food Code, this training is a Person in Charge responsibility (§2-103.11(O)). Many states now require allergen awareness training as a condition of food handler certification, and California enacted SB 68 in October 2025; beginning July 1, 2026, covered large chain restaurants must provide written major-allergen information for menu items.

Allergen Labeling Requirements

For packaged food, FALCPA (as amended by the FASTER Act) requires major food allergens to be declared on the label in plain English. The two acceptable methods are: (1) within the ingredient list, with the allergen source in parentheses (e.g., "lecithin (soy)"); or (2) immediately after or adjacent to the ingredient list, in a "Contains" statement (e.g., "Contains: wheat, milk, soy").

For unpackaged foods served in restaurants, delis, cafeterias, and other retail establishments, the 2022 Food Code §3-602.12 added a written-notification requirement for major allergens. In jurisdictions that have adopted §3-602.12, the notification can take many forms: menu allergen indicators, deli case signage, table tents, placards, or printed allergen guides available on request. Verbal-only disclosure ("just ask your server") is no longer compliant in jurisdictions that have adopted the 2022 Code provision.

What the Exam Tests

Food handler and ServSafe exam questions on allergens typically test four things:

The list of nine allergens. Be ready to identify which foods are on the list and which are not — for example, mollusks (clams, oysters) are common allergens but not on the federal "major" list; mustard is a common allergen in Canada and the EU but not on the U.S. list.
The cross-contact vs cross-contamination distinction. Cross-contact = allergen transfer; cross-contamination = pathogen transfer. Cooking destroys most pathogens; it does not destroy allergens.
Person in Charge responsibilities. The PIC must ensure employees are trained in allergen awareness and that allergen communication systems function from order to delivery.
Customer communication. The required response to a customer disclosing an allergy is to acknowledge it, communicate it to the kitchen, and ensure the dish is prepared on dedicated or freshly cleaned equipment — never to dismiss the disclosure or guess at ingredients.

FAQ

How many major food allergens does U.S. federal law recognize?: Nine, as of January 1, 2023. The original eight under FALCPA (2004) were milk, eggs, fish, crustacean shellfish, tree nuts, peanuts, wheat, and soybeans. The FASTER Act of 2021 added sesame as the ninth major food allergen effective January 1, 2023.
What is the difference between cross-contact and cross-contamination?: Cross-contact is the unintentional transfer of a food allergen (such as peanut residue on a knife) to a food that wasn't supposed to contain it. Cross-contamination is the transfer of harmful microorganisms (pathogens) from one food, surface, or person to another. Cross-contamination can be controlled by cooking to a proper internal temperature; cross-contact cannot, because cooking does not destroy allergenic proteins.
Are mollusks (oysters, clams, mussels, scallops) on the federal major-allergen list?: No. The federal list of nine major food allergens covers crustacean shellfish (crab, lobster, shrimp, crawfish) but not mollusks. However, mollusk allergies are real and serious, and many restaurants treat mollusks as a major allergen voluntarily.
Does cooking destroy food allergens?: No. Allergenic proteins are heat-stable. Cooking, frying, or baking will not eliminate the risk of an allergic reaction. The only effective control is preventing the allergen from contacting the food in the first place — through ingredient awareness, dedicated equipment, proper cleaning, and trained staff.
What does the 2022 FDA Food Code require for allergen communication?: Two things. First, the Person in Charge must demonstrate knowledge of the major food allergens and ensure food employees are trained in food allergy awareness (§2-102.11 and §2-103.11(O)). Second, for unpackaged foods served or sold to consumers, §3-602.12 requires written notification of major allergens in jurisdictions that have adopted the 2022 Food Code provision — for example, menu indicators, deli case signage, or printed allergen guides. Verbal-only disclosure is not sufficient in those jurisdictions.
Is sanitizer enough to remove allergen residue from a surface?: No. Sanitizer reduces microbial load; it does not remove allergenic proteins. Allergen-contaminated surfaces must be physically cleaned with hot soapy water, rinsed, and then sanitized. Wiping a surface with a sanitized cloth — even an EPA-registered sanitizer — does not eliminate allergen residue.

Bottom Line

Allergen cross-contact prevention is one of the most heavily tested topics on modern food handler certification exams, and the allergen landscape has changed materially since sesame became the ninth major allergen in 2023 and the 2022 Food Code added written-notification language for unpackaged foods. Memorize the nine major food allergens — milk, eggs, fish, crustacean shellfish, tree nuts, peanuts, wheat, soybeans, and sesame (the newest, added by the FASTER Act effective January 1, 2023). Understand that cross-contact is allergen transfer, not pathogen transfer, and that cooking does not neutralize allergenic proteins. Know that under the 2022 FDA Food Code, the Person in Charge is responsible for allergen-awareness training (§2-103.11(O)), and unpackaged foods require written allergen notification to consumers in jurisdictions that have adopted §3-602.12. Prevention rests on ingredient awareness, dedicated or properly cleaned equipment, accurate communication from order to plate, and trained staff. For the operational protocols servers and cooks should follow day-to-day, see our food allergen procedures for servers and cooks guide.

Source: FDA — The FASTER Act: Sesame Is the Ninth Major Food Allergen · FDA — Addition to the 2022 Food Code: Sesame Added as a Major Food Allergen · FDA — Food Allergies