Class 1 recalls are defined as situations where there is a reasonable probability that the use of or exposure to a food product will cause serious adverse health consequences or death to humans. Residues of most of the so-called "Big 8" (and soon-to-be "Big 9," with the recent addition of sesame seeds) allergenic foods are considered as a basis for Class 1 recalls. While food allergen recalls are unwelcome, potentially valuable lessons can be learned from these unfortunate events. Good manufacturing practices (GMPs) have evolved from corrective actions taken to prevent allergen recalls.