3204.16 - Reactive dyes and preparations based thereon:

This category, HTS 3204.16, encompasses reactive dyes and preparations based on them. Reactive dyes are characterized by their ability to form a covalent bond with the fiber being dyed, resulting in excellent wash fastness. These dyes are widely used for coloring cellulosic fibers such as cotton and linen, as well as some protein fibers like wool and silk, and even synthetic fibers like nylon. The preparations may include mixtures of dyes, diluents, or other additives designed to enhance their application properties or performance.

Within the broader group of synthetic organic coloring matter (3204.1), this specific subdivision differentiates itself from sibling categories by the chemical mechanism of its interaction with the substrate. Unlike disperse dyes (3204.11) which are non-ionic and physically penetrate fibers, or acid dyes (3204.12) which rely on ionic attraction, reactive dyes create a permanent chemical linkage. This distinguishes them from direct dyes (3204.14) which also dye cellulosic fibers but through weaker hydrogen bonding.

The subcategories under 3204.16 provide for specific classifications based on the chemical identity of the reactive dyes. Subcategory 3204.16.10.00 enumerates specific named reactive dyes and common mixtures, while 3204.16.20.00 captures a more extensive list of other reactive dyes and complex preparations, often identified by their chemical composition and precise color index numbers. The final subdivision, ": Other:", accounts for any reactive dyes or preparations not explicitly listed in the preceding subcategories, ensuring comprehensive coverage.