For food manufacturers, finding an unintentional allergen during routine testing is never welcome news. But it’s also exactly why testing is so important. Even with strong food safety protocols in place, unexpected issues can arise. Ingredients change, equipment is shared, cleaning procedures may not work as intended, and allergens can sometimes find their way into products where they don’t belong.
With approximately 33 million Americans living with at least one food allergy, identifying potential allergens before products reach consumers is incredibly important. So, what happens when routine testing identifies an allergen that shouldn’t be there? The answer isn’t simply to run another test and hope for a different result. It’s about taking action, understanding what went wrong and making sure it doesn’t happen again.
First Things First: Stop, Investigate and Determine the Scope
When an unexpected allergen is detected, the first priority is protecting consumers. That means placing potentially affected ingredients or finished products on hold, stopping relevant production activities when necessary and beginning an investigation.
The next step is determining how far the issue might extend. Is it limited to one ingredient lot? Could multiple production batches be affected? Was the same equipment used to manufacture other products?Manufacturers need to look at the bigger picture before deciding what can safely move forward.
This is where detailed production records become incredibly valuable. Batch records, ingredient documentation, supplier information, equipment usage, and cleaning, sanitation and pre-operational surface testing logs/records can help teams trace where the allergen may have entered the process. Cleaning procedures also deserve a closer look. Was the equipment cleaned according to established protocols? Were those procedures followed correctly? Is there evidence that cleaning was effective?
Recent food recall data shows just how important allergen management is. According to a 2026 report from the U.S. Public Interest Research Group (PIRG), undeclared allergens were the leading cause of food recalls in 2025, accounting for nearly 39% of all recalls. It’s a reminder of why reviewing ingredients, verifying cleaning procedures and catching potential issues before products reach consumers matters so much.
Finding the Cause and Making It Right
Once potentially affected products have been identified and contained, the next step is to conduct a root-cause analysis to determine how the allergen entered the product and why existing controls failed to prevent it. Potential causes may include inadequate cleaning procedures, equipment design flaws, shared cleaning tools or utensils, improper production scheduling or changeovers, airborne cross-contact, and improper handling of rework or work-in-progress products. Other contributing factors may include supplier allergen control failures, ingredient misidentification, accidental spills in shared storage areas, human error, or mishandling of products during transit. Identifying the underlying cause allows manufacturers to address gaps in their allergen control procedures, implement corrective actions, and reduce the risk of similar incidents occurring in the future.
Milk is a particularly important example. According to the FDA, milk accounted for more than one-third of food recalls involving undeclared allergens during the decade examined by the agency. Even familiar ingredients can present serious risks when allergen controls fall short. Whatever the cause, the goal is to address the underlying issue rather than simply treating the immediate problem.
Corrective actions may include updating cleaning procedures, retraining employees, improving ingredient verification, adjusting production schedules, and strengthening communication with suppliers. If a supplier is involved, manufacturers may need to investigate the issue, request corrective actions, reevaluate their supplier approval program, or increase the frequency of supplier audits and lot-by-lot testing. Retesting ingredients, surfaces, or finished products can also help with the investigation and assess whether corrective measures have been effective. However, because allergens may not be evenly distributed throughout a lot, re-testing should be used as part of the investigation. If an undeclared allergen is confirmed to be present in a product, it cannot be released for distribution because it may pose a serious health risk to consumers with food allergies.
Communication is equally important throughout this process. Quality assurance teams, production managers, suppliers and certification partners may all need to be involved. If potentially affected products have already entered distribution, additional notifications, recall evaluations and regulatory steps may be necessary. The key is having a clear process in place before an issue occurs.
Why Ongoing Testing Matters
A product that meets allergen-free standards today still needs effective controls tomorrow, next month and next year. That’s why ongoing monitoring plays such an important role in maintaining allergen-free claims. Routine testing, facility audits, employee training and accurate documentation all work together to help manufacturers identify potential problems before they become bigger ones.
And while discovering an unintentional allergen can be stressful, a strong response demonstrates that a manufacturer’s food safety systems are doing what they’re designed to do: identify risks, prompt action and support continuous improvement. Maintaining that level of accountability is a key part of Certified Free From™ (CFF) Allergens certification.
CFF goes beyond reviewing an allergen-free claim at a single point in time. Through third-party verification, ongoing monitoring, facility audits and testing requirements, the program helps manufacturers substantiate their claims and maintain the controls behind them. Because earning certification is just the beginning. Maintaining consumer confidence takes an ongoing commitment to food safety.
Ready to learn more about Certified Free From™ certification? Visit CFF Foods to explore how certification can help your brand build confidence in its allergen-free claims.