Brown FK

Brown FK, also called Kipper Brown, Chocolate Brown FK, and C.I. Food Brown 1, is a brown mixture of six synthetic azo dyes, with addition of sodium chloride, and/or sodium sulphate. It is very soluble in water. Its CAS number is.

The dyes it contains are:
 * 4-(2,4-diaminophenylazo)benzenesulfonate, sodium salt
 * 4-(4,6-diamino-m-tolylazo)benzenesulfonate, sodium salt
 * 4,4'-(4,6-diamino-1,3-phenylenebisazo)-di(benzenesulfonate), disodium salt
 * 4,4'-(2,4-diamino-1,3-phenylenebisazo)-di(benzenesulfonate), disodium salt
 * 4,4'-(2,4-diamino-5-methyl-1,3-phenylenebisazo)-di(benzenesulfonate), disodium salt
 * 4,4',4''-(2,4-diaminobenzene-1,3,5-trisazo)-tri(benzenesulfonate), trisodium salt

When used as a food dye, its E number is E154. It is used in smoked and cured mackerels and other fish, but also in some cooked hams and other meats, and crisps. It yields healthy color that does not fade during cooking, nor tends to leach.

It is one of the colourants that the Hyperactive Children's Support Group recommends be eliminated from the diet of children, especially when in combination with benzoates. It can provoke allergic reactions in people sensitive to salicylates, and can intensify the symptoms of asthma. It is banned in the European Union (with exception of the United Kingdom), Australia, Austria, Canada, United States, Finland, Japan, Ireland, Sweden, Switzerland, New Zealand, and Norway.