2922.21.10.00—1-Amino-8-hydroxy-3,6-naphthalenedisulfonic acid; 4-Amino-5-hydroxy-1,3-naphthalenedisulfonic acid (Chicago acid); 4-Amino-5-hydroxy-1,3-naphthalenedisulfonic acid, potassium salt; 4-Amino-5-hydroxy-1,3-naphthalenedisulfonic acid, sodium salt; 4-Amino-5-hydroxy-2,7-naphthalenedisulfonic acid, monosodium salt (H acid, monosodium salt); 4-Amino-5-hydroxy-2,7-naphthalenedisulfonic acid, potassium salt (H acid, monopotassium salt); 4-Amino-3-hydroxy-1-naphthalenesulfonic acid; 6-Amino-1-naphthol-3-sulfonic acid and its salts; and 8-Amino-1-naphthol-5-sulfonic acid and its salts