Undeclared allergen recalls: what they mean and what to do

Guide · Updated October 13, 2026 · Based on FDA, CDC and FoodSafety.gov guidance (sources below)

Not medical advice. This guide summarizes public information from U.S. government health agencies for general education. It is not a substitute for advice from a doctor, pharmacist or other qualified health professional. If you have symptoms or questions about your health, contact a health professional. In an emergency, call 911.

Scroll through any week of FDA recall notices and you will see phrases like "undeclared milk," "undeclared peanut" or "undeclared sesame." These recalls do not mean the food is spoiled or contaminated with germs. They mean the food contains a common allergen that is not listed on the label. For most people that is harmless, but for someone with that allergy it can be dangerous. This guide explains how allergen labeling works and what to do if you have an affected product.

The nine major food allergens

The FDA recognizes nine major food allergens in the United States:

• Milk
• Eggs
• Fish (such as bass, flounder or cod)
• Crustacean shellfish (such as crab, lobster or shrimp)
• Tree nuts (such as almonds, pecans or walnuts)
• Peanuts
• Wheat
• Soybeans
• Sesame

The first eight were named in the Food Allergen Labeling and Consumer Protection Act of 2004 (FALCPA). The FDA notes that when FALCPA passed, these eight accounted for 90 percent of food allergies and serious allergic reactions in the US. Sesame was added as the ninth by the FASTER Act, effective January 1, 2023. The FDA also notes that more than 160 foods have been identified as causing allergies in sensitive people.

How allergens must be labeled

Under federal law, a packaged food's label must identify the food source of any major allergen it contains. The FDA explains that this can be done in one of two ways:

1. In the ingredient list, in parentheses after the ingredient, such as "whey (milk)" or "flour (wheat)."
2. In a "Contains" statement right after or next to the ingredient list, such as "Contains wheat, milk, and soy."

The label must also name the specific type of tree nut, fish or shellfish. These rules apply to most packaged foods regulated by the FDA, including dietary supplements. They do not cover meat, poultry and egg products regulated by the USDA, or most foods sold unpackaged at restaurants.

Labels sometimes also say "may contain" or "made in a facility that also processes." The FDA says these advisory statements are not required by law and must be truthful and not misleading.

Why undeclared allergen recalls happen

The FDA says food facilities must have written controls to prevent allergen cross-contact (an allergen accidentally getting into a product) and to make sure labels are accurate. When those controls fail, a product can end up with an allergen that is not on the label.

The FDA reports that, based on reports to its Reportable Food Registry from September 2009 to September 2014, about one-third of foods reported as serious health risks involved undeclared allergens. Milk was the most common major allergen behind these recalls, and the most common food types were bakery products, snack foods, candy, dairy products and dressings such as sauces and gravies. The FDA has also received many reports of undeclared milk in dark chocolate.

When a problem is found, the FDA says it works with companies to recall products and notify the public. Many of the undeclared allergen recalls in recent FDA enforcement reports are rated Class I, the most serious class.

Symptoms of an allergic reaction

The FDA says symptoms usually appear within a few minutes to a few hours of eating the food. They can include:

• Hives, flushed skin or rash
• Tingling or itching in the mouth
• Swelling of the face, tongue or lips
• Vomiting, diarrhea or stomach cramps
• Coughing or wheezing
• Dizziness or lightheadedness
• Swelling of the throat, difficulty breathing or loss of consciousness

A severe, life-threatening reaction is called anaphylaxis. The FDA advises that anyone with a known food allergy who starts having symptoms should stop eating the food, consider whether to use emergency medication such as epinephrine, and seek medical attention. In an emergency, call 911.

What to do if you have a recalled product

If no one in your household has the allergy named in the recall, the product is generally not a risk to you, but follow the recall notice for returns or disposal.

If someone in your home does have that allergy, FoodSafety.gov recommends:

• If the product has not been served, throw it away or return it to the store for a refund.
• If the product has been served, wash any surfaces it may have touched, including plates, pots and pans, utensils and counters, with soap and water.

Before throwing it away, check that your package matches the recall. Our guide on how to check if your food has been recalled explains how to compare lot codes and dates.

Reporting a reaction

If you have symptoms, contact your healthcare provider first. You can also report a reaction or labeling problem to the FDA. The FDA asks for details such as where you bought the product, what symptoms you had and how soon they started, any treatment, and the codes on the label, plus photos of the label, ingredient list and lot code if possible.

Staying ahead of allergen recalls

People managing food allergies already read labels closely. Checking recalls adds another layer of protection, especially for foods that the FDA says are most often involved: baked goods, snacks, candy, dairy and sauces. You can browse recent allergen recalls on our food recalls page, or sign up below for a short email digest.

Sources

• FDA: Food Allergies
• FoodSafety.gov: Recalls and Outbreaks
• FoodSafety.gov: Food Poisoning
• FDA: Recalls, Market Withdrawals, & Safety Alerts