Black PN comprises mainly of naphthalene; 1,7-disulfonate; tetrasodium-4-acetamido-5-hydroxy-6-[7-sulfonato-4'-(4-sulfonatophenylazo)-1-naphthylazo]as well as other subsidiary coloring matter that can be used in combination with sodium chloride/sodium sulfate as principal uncolored component. Black PN is described as the sodium salt.

The calcium and the potassium salt are also permitted. The organic compounds other than coloring matters it contains include 4-amino-5-hydroxynaphthalene-1,7-disulfonic acid; 4-acetamido-5-hydroxynaphthalene-1,7-disulfonic acid; 4,4'-diazoaminodi-(benzenesulfonic acid) and 8-aminonaphthalene-2-sulfonic acid which in total is not more than 0.8%.