3204.12.50 - Other

This HTS category, "Other," within the classification of Acid dyes and preparations based thereon, encompasses synthetic organic coloring matters that are chemically defined as acid dyes but do not fall under any more specific sub-classification. Acid dyes are typically water-soluble anionic dyes that are applied to fibers such as wool, silk, nylon, and modified acrylics, where they form ionic bonds with cationic sites on the fiber. This broad designation covers a wide array of acid dyes that do not meet the specific criteria of premetallized acid dyes or other explicitly defined categories.

Distinguishing this "Other" category from its sibling, 3204.12.45, is crucial. The sibling category specifically refers to products described in additional U.S. note 3 to section VI, which often pertains to particular dyes or pigments with specific applications or origins stipulated by U.S. trade regulations. Therefore, 3204.12.50 is reserved for acid dyes that are not subject to such specific additional U.S. notes and are classified solely based on their chemical nature as acid dyes and their preparations.

The subcategories under 3204.12.50 provide further specificity for commonly encountered acid dyes. These include widely used food colorants like FD&C red 40, FD&C yellow 5, and FD&C yellow 6, each identified by its CAS number for precise identification. The "Other" subcategory (3204.12.50.90) then captures any remaining acid dyes and their preparations that do not fit into these specific food colorant designations, ensuring comprehensive coverage within the broader classification of acid dyes.