ABSTRACT: The gluten analysis of foods has long had limitations, which have precluded food standards authorities from issuing standards for gluten-free foods based on final gluten content. The Codex Alimentarius and the Food and Drug Administration have taken steps towards such standards in which they favour the R5-enzyme-linked immunosorbent assay for gluten analysis. If this method is to be widely employed, its limitations should be recognised. Above all, it should be noted the ability of R5-enzyme-linked immunosorbent assay, and other methods, to measure gluten's toxicity toward celiac disease patients is not validated clinically. Gluten is a complex mixture of proteins and its toxicity is not fully understood. Analytical methods are a valuable tool in the definition of gluten-free foods, but they should be employed with appropriate caveats in ensuring the safety of the foods.