2921.49.32.00 - Fast color bases

This classification, "Fast color bases," encompasses aromatic amines and their derivatives that are specifically designed for use as intermediates in the production of azo dyes and pigments. These compounds are characterized by their ability to undergo diazotization and coupling reactions, forming brightly colored and stable colorants. Their primary function in this context is to serve as the "base" component in the synthesis of these fast dyes and pigments, contributing significantly to their final shade, fastness properties, and application suitability in textiles, inks, and plastics.

Distinguishing "Fast color bases" from its sibling category "Drugs" is crucial. While both may fall under the broader umbrella of aromatic monoamines and their derivatives, the intended use is the primary differentiating factor. "Drugs" refers to substances intended for medicinal or pharmaceutical purposes, often regulated under different legal frameworks. In contrast, fast color bases are strictly industrial chemicals whose primary application lies in the colorant industry, not for therapeutic use.

As a leaf node, this classification does not have further subdivisions. Therefore, practical classification relies on understanding the chemical structure typical of aromatic amines intended for dye synthesis and their known applications. If a product is an aromatic amine derivative marketed and used as an intermediate in the production of fast azo dyes and pigments, it would be classified here, assuming it does not meet the criteria for other more specific subdivisions within Chapter 29 that may exist at higher levels.