Brilliant Black BN, Brilliant Black PN, Brilliant Black A, Black PN, Food Black 1, Naphthol Black, C.I. Food Black 1, or C.I. 28440, is a synthetic black diazo dye. It is soluble in water. It usually comes as tetrasodium salt. It has the appearance of solid, fine powder or granules. Calcium and potassium salts are allowed as well.