What is E131?

Patent Blue V, also called Food Blue 5, Sulphan Blue, Acid Blue 3, L-Blau 3, C-Blau 20, Patentblau V, Sky Blue, or C.I. 42051, is a sky blue synthetic triphenylmethane dye used as a food coloring. E131 sits in the E100–E199 series, which in the EU classification mainly covers colours.

What is E131 used for?

E131 belongs to the colours group. Colours are added to give or restore colour to food. Some are natural, like curcumin from turmeric; some synthetic dyes are debated and require warning labels in the EU.

Is E131 safe?

E131 is rated “moderate”. It is approved for use in food, but some people prefer to limit it. “Moderate” means it is approved, but is debated or something some people prefer to limit.

How E131 appears on labels

On food packaging you'll find E131 either as the number “E131” or by the name “Patent Blue V” in the ingredient list, often after its function. Ingredients are listed in descending order by weight, so an additive near the end is present only in small amounts.

Is E131 vegan?

Yes, E131 is suitable for vegans.