Understanding food allergen thresholds and developing a sound scientific framework for such thresholds is also likely to be useful in addressing food allergen cross-contact issues, including the use of advisory labeling.
Both as part of its ongoing risk management of food allergens and in response to FALCPA, CFSAN established an ad hoc internal, interdisciplinary group (the Threshold Working Group) to evaluate the current state of scientific knowledge regarding food allergies and celiac disease, to consider various approaches to establishing thresholds for food allergens and for gluten, and to identify the biological concepts and data needed to evaluate the scientific soundness of each approach. This report is the result of the working group’s deliberations.
This report summarizes the current state of scientific knowledge regarding food allergies and celiac disease, including information on dose-response relationships for major food allergens and for gluten, respectively. The ability to establish a threshold depends on understanding the dose-response relationship between the ingestion of an allergen or gluten and the elicitation of an adverse response. Implicit in establishing such dose- response relationships is the identification of susceptible populations and characterization of any exposure levels below which all, or part, of the susceptible population does not respond. There is no consensus in the scientific literature regarding thresholds for major food allergens or gluten. Therefore, the Threshold Working Group identified the biological concepts and data needed to evaluate various approaches for establishing thresholds that would be scientifically sound and efficacious in relation to protection of public health.
B. Definitions of Thresholds The term “threshold” has been used to refer to a variety of different concepts (Table I-1) that apply either to individuals or populations. Thresholds can be measured experimentally in animals or humans [i.e., No Observed Adverse Effect Level (NOAEL) or Lowest Observed Adverse Effect Level (LOAEL)], derived from epidemiological data, estimated by modeling (statistical or simulation), established by statute, or arising as the result of the selection of an analytical method. The ability to measure or determine a threshold may be limited by the sensitivity and specificity of the methods available to measure either the stimulus or the response. Understanding the strengths and limitations of the data underpinning the different approaches is particularly important when dealing with adverse effects that have low probabilities of occurring.
Table I-1. Summary of Various Types of Thresholds
Type Etymological Definition Toxicological
Description “The intensity below which a mental or physical stimulus cannot be perceived and can produce no response.” (Webster’s Dictionary). The dose at, or below which, an adverse effect is not seen in an experimental setting.
The limit of detection of an analytical method. The establishment of a limit by statute, below which no regulatory action will be taken.
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