The issue of allergen-related food recalls is arguably of greatest concern and least understood in the food industry. Since the enactment of the U.S. Food and Drug Administration's (FDA's) Food Safety Modernization Act (FSMA) in 2011, increasing numbers of allergen-related food recalls are seen, indicating that the industry is still struggling with designing and implementing effective allergen controls.

The vast majority of issues with undeclared allergens in food are unintentional. Undeclared allergens continue to be responsible for the highest percentage of reported FDA food recalls, entering the food supply through: