2832.30 - Thiosulfates:

This HTS category, 2832.30, specifically covers thiosulfates, which are salts or esters of thiosulfuric acid. These inorganic compounds are distinct from sulfites, which are covered under sibling categories 2832.10 and 2832.20. While both families of compounds contain sulfur and oxygen, thiosulfates possess an additional sulfur atom in a unique bonding arrangement, differentiating their chemical properties and applications.

Within this thiosulfate classification, further subdivisions are made to distinguish between specific types. The subcategory 2832.30.10.00 addresses sodium thiosulfate, commonly known as "hypo," which has widespread use in photography for fixing negatives and prints, as well as in water treatment and as an analytical reagent. The remaining thiosulfates, not specifically sodium thiosulfate, are classified under 2832.30.50.00. This latter category would encompass thiosulfates of other metals, such as potassium or ammonium thiosulfate, used in diverse industrial processes, including dyeing, tanning, and as reducing agents in chemical synthesis.