2831.90.00.00 - Other

This HTS category, 2831.90.00.00, encompasses dithionites and sulfoxylates that are not specifically classified under the heading for those of sodium. Dithionites are strong reducing agents, commonly used in the textile industry as vat dyeing reducing agents and in the pulp and paper industry for bleaching. Sulfoxylates are salts of sulfoxylic acid and also function as reducing agents, finding applications in photography and chemical synthesis.

The distinction between this category and its sibling, 2831.10, lies in the chemical composition and the counter-ion. While 2831.10 specifically covers dithionites and sulfoxylates where sodium is the counter-ion (e.g., sodium dithionite, sodium formaldehyde sulfoxylate), this category is for all other dithionites and sulfoxylates. This would include compounds where other alkali metals, alkaline earth metals, or other cations form the salt.

As a leaf node, this classification does not have further subdivisions. Therefore, the practical classification relies on identifying the chemical substance as a dithionite or sulfoxylate and confirming that it is not a sodium salt, thereby directing it to this residual category. Examples would include potassium dithionite or zinc formaldehyde sulfoxylate.