Scientists have improved knowledge about the doses of food allergens that can result in allergic reactions.

The UN Food and Agriculture Organization (FAO) and World Health Organization (WHO) Expert Consultation on Risk Assessment of Food Allergens met to establish the level of several food allergens that are not expected to result in serious health risks among the majority of consumers.

The committee considered four approaches to define thresholds: analytical-based; no observed adverse effect level [NOAEL] and uncertainty factor [UF]; benchmark dose [BMD] with/without margin of exposure (MoE); and probabilistic hazard assessment before opting for the latter and benchmark dose without MoE.

They agreed that the thresholds, also known as reference doses (RfD), should conform with a definition of health-based guidance values.

Experts noted the rarity of fatal food anaphylaxis and observed that no fatal reactions had been reported following exposure at or below amounts considered for RfD. The committee agreed that, for all priority allergens, safety would be met by using ED05 as the foundation for defining RfDs. Population-based eliciting doses (EDs) may be expressed as ED05 or ED01, as doses causing reactions in 5 percent or 1 percent of people, respectively.

Establishing thresholds
The resulting RFDS expressed as milligrams (mg) of total protein from the allergenic source were: 1 mg: walnut and pecan; cashew and pistachio; and almond; 2 mg: peanut, sesame seed, cow’s milk, and egg; 3 mg: hazelnut; 5 mg: wheat, fish, and 200 mg: crustaceans like shrimp, prawns, crabs, and lobsters.

Reference doses need to be converted into action levels of so many milligrams of total protein from the allergenic source per kilogram of food.

The primary purpose of the RfD is to improve the management of unintended allergen presence in foods, which includes the use of Precautionary Allergen Labeling (PAL). It is not intended to be used to define allergen-free labeling.

Knowledge of thresholds is important to assess the risks from allergens and put in place risk management and mitigation strategies. Risk management options might include the implementation of PAL, monitoring of allergens in the supply chain or in production facilities, and management of health hazards from unintended allergen presence, according to the report.

It was the second of four expert meetings. The first in 2020 reviewed and validated a Codex priority allergen list, part three in 2021 looked at the evidence in support of precautionary labeling and part four in November 2022 studied exemptions for food allergens.

Those involved in part two of the report included Bert Pöpping, of FOCOS; Stephen Taylor, from the University of Nebraska-Lincoln; Patrick O’Mahony, of the Food Safety Authority of Ireland; Sébastien La Vieille, at Health Canada, and Lauren Jackson, of CFSAN at the U.S. Food and Drug Administration.