2908.99.03

Halogenated, sulfonated, nitrated or nitrosated derivatives of phenols or phenol-alcohols: Other: Other: Derivatives containing only sulfo groups, their salts and esters: 2,5-Dihydroxybenzenesulfonic acid, potassium salt; 3,6-Dihydroxy-2,7-naphthalenedisulfonic acid; 3,6-Dihydroxy-2,7-naphthalenedisulfonic acid, sodium salt; 4-Hydroxy-1-naphthalenesulfonic acid, sodium salt; 1-Naphthol-3,6-disulfonic acid; and 2-Naphthol-3,6-disulfonic acid and its salts