Benzenesulfonic acid,4-((2,4-diaminophenyl)azo)-,monosodium salt, C.I. DIRECT BROWN 191, Sodium p-((2,4-diaminophenyl)azo)benzenesulphonate, sodium 4-[(E)-(2,4-diaminophenyl)diazenyl]benzenesulfonate, EINECS 233-460-8, Padding Brown N, Padding Brown J