Food allergy has increased in recent decades and has a major impact on patients' quality of life. There is currently no treatment in routine clinical practice, and patients are often faced with accidental reactions. Precautionary allergen labelling (PAL) has been used by the food industry to attempt to minimize this risk, although not standardized and often ambiguous. Estimating the risk of reacting to traces in foods is complicated by heterogeneous amounts of allergens in foods with precautionary labelling and individual variability in reaction thresholds. In recent years, oral food challenge studies have shown that low individual reaction thresholds do not necessarily correlate with severe reactions, and current understanding of thresholds is evolving with novel low-dose challenge protocols better adapted to estimate them. Future tools to provide a better estimation of minimal eliciting doses, including basophil activation tests, may improve our management of food-allergic patients.