The recently convened FAO/WHO experts agreed that RfDs for gluten for the PAL framework should not be used as the basis for defining gluten-free labeling, and that establishing a reference dose (RfD) for gluten is important for precautionary labeling of products that do not have a gluten-free label. Establishing RfD(s) for gluten in celiac disease requires a different basis than that used for IgE-mediated food allergies and must reflect long-term exposure risks.

Therefore, the experts conducted risk assessments to evaluate a RfD for gluten based on chronic gluten exposure, rather than making decisions based on single exposures, as has been done for IgE-mediated food allergy. The goal was to ensure the cumulative daily dose does not exceed 10 mg gluten based on a consideration of daily intake of food from multiple individual eating occasions.

Modeling reflective of chronic or cumulative daily exposure was conducted for potential gluten RfDs (1–⁠10 mg of gluten), with parameters including frequency of cross-contact, concentration of gluten in a product when cross-contact is present, and intake amounts of foods per day. The modeling included products with concentrations of gluten greater than 20 mg/kg per eating occasion and no risk communication regarding cereals containing gluten. With realistic parameters, gluten RfDs of 5–⁠10 mg did not result in median daily gluten exposures exceeding 10 mg.

The analyses indicated that maximum limits even with acute RfDs above 5 mg gluten could protect individuals with celiac disease from chronic exposures exceeding 10 mg per day. To avoid different RfDs for the same foods, the experts agreed to recommend a RfD of 4 mg gluten for making risk-based decisions about applying PAL for cereals containing gluten. The experts recommend that for guidance on PAL, the previously established RfD of 5 mg total protein for wheat should be replaced with an RfD of 4 mg gluten.

The experts also recommend that, where gluten-containing cereals are present in the ingredient list (e.g., barley), and the food contains cross-contact above the RfD from other gluten containing cereals (e.g., wheat), competent authorities should consider how the specified cereal name and the optional term “gluten” appear in the ingredient list, separate statement, and the PAL statement “may contain” to avoid consumer confusion.