In contrast to usual ingredients in processed packaged foodstuffs, there are no suitable and binding regulations for the labeling of unintentional allergen traces in these foods as yet. This situation is unsatisfactory in regard to the fact that even traces of undeclared "hidden" allergens can constitute a considerable health risk for food allergic consumers. Furthermore, the unintentional cross-contact (cross-contamination) of allergens is also an issue in regard to food manufacturer product liability and due diligence. Therefore, stakeholders consider imperative need for the scientific determination of maximum tolerable levels of allergen traces in order to establish thresholds for legally binding food labeling. In addition to conventional toxicological risk assessments, the risk assessment of allergen traces that would be necessary in this context nowadays also incorporates modern approaches such as benchmark procedures and probabilistic modeling and methods. The scientific debate concerning the establishment of safe threshold levels continues, and a consensus must still be reached.