Disperse dyes are water-insoluble colorants applied to hydrophobic fibers (primarily polyester) from aqueous dispersion. Solvent dyes, classified under 320419, are soluble in organic solvents and used in fuels, waxes, and plastics rather than textile dyeing. The application medium and fiber substrate are the key classification signals; the dye's technical data sheet typically identifies the dye class.

Many tariff lines within this heading for goods of Chinese origin are subject to Section 301 measures. The measure applies at the specific 10-digit HTS line level, so importers should verify each line's status and ensure accurate country-of-origin documentation, particularly for dyes processed or blended in third countries.