Patent Blue V

Patent Blue V is a synthetic triarylmethane dye that produces a bright cerulean-blue colour. It is used in confectionery, beverages, ice cream, and baked goods where a vivid blue shade is desired. In the EU it is one of the colourants identified in the 2007 Southampton study examining behavioural effects of certain dye combinations in children.

JECFA's ADI is 15 mg per kilogram body weight per day, established in 1975. This ADI provides a wide safety margin at typical dietary exposures. However, Patent Blue V belongs to the same structural class of synthetic dyes (triarylmethanes and related compounds) flagged by the Southampton study, which found that combinations of certain artificial colours together with sodium benzoate (E211) were associated with increased hyperactivity in children. The EU responded by requiring a warning label on products containing these dyes.

Patent Blue V is not permitted in the United States or Canada, but is approved in the EU and some other markets. In the EU, any product containing E131 requires the advisory text: "may have an adverse effect on activity and attention in children." Consumers who prefer to avoid synthetic dyes — particularly for children — should check labels for E131. For healthy adults, typical dietary exposures fall well below the JECFA ADI and are not considered a toxicological concern.