Brown FK

Brown FK is notable for histamine, salicylate, nickel, FODMAPs and tyramine. Clear on lactose, gluten, fructose, oligosaccharides, sorbitol, sucrose and oxalates.

Yes — Brown FK is high in histamine. Brown FK is not one dye but a mixture of six, and its EU authorisation covers exactly one food: smoked kippers. If you are not eating kippers you are almost certainly not eating this. Where it is used, it belongs to the colour class removed on a pseudoallergen-free diet. None of this is about histamine content: a colour carries none. Colours are on this page because the pseudoallergen-free elimination diet removes them as a class, and that diet is itself unproven in double-blind trials.

Yes — Brown FK is high in salicylate. A synthetic brown dye historically used on smoked fish, and one of the colours grouped with the azo dyes as a salicylate cross-reactor.

Brown FK contains moderate levels of nickel. Brown FK is a mixture of azo dyes. Nothing in the molecule contains nickel, but nickel is the workhorse catalyst of industrial organic synthesis, and a trace of the catalyst survives into the product. For this additive there is no legal nickel ceiling at all.

Brown FK contains only low levels of FODMAPs. Brown FK is a mixture of azo dyes, and there is no fermentable carbohydrate in it. Amounts vary by brand and recipe, so always check the label of the exact product.