3824.99.25.00 - Aqueous mixtures of triphenyl sulfonium chloride, diphenyl (4-phenylthio)phenyl sulfonium chloride and (thiodi-4,1- phenylene)bis(diphenyl sulfonium) dichloride

This HTS category, 3824.99.25.00, specifically classifies aqueous mixtures containing significant amounts of aromatic sulfonium salts. These complex chemical preparations include triphenyl sulfonium chloride, diphenyl (4-phenylthio)phenyl sulfonium chloride, and (thiodi-4,1-phenylene)bis(diphenyl sulfonium) dichloride. Their primary application is often as photoinitiators or components in photopolymerization processes, particularly in the electronics and coatings industries, where they generate reactive species upon exposure to light.

Distinguishing this category from its siblings, 3824.99.21.00 covers substances derived from coal tar, a distinctly different origin. Sibling category 3824.99.26.00 encompasses a diverse array of other chemical mixtures, none of which are aqueous sulfonium salt preparations. The "Other" subcategory (3824.99.29.00) serves as a residual for any preparations not specifically identified elsewhere within the broader "Other" heading.

As a leaf node, 3824.99.25.00 represents a specific chemical compound or mixture that is not further subdivided. Therefore, classification within this code hinges on the precise identification of these named sulfonium salts and their presentation as an aqueous mixture, meeting the "5 percent or more by weight of one or more aromatic or modified aromatic substances" criterion. The presence of water as the primary solvent is a key distinguishing factor from potentially anhydrous solid forms of these same compounds.