2835.29 - Other:

This HTS category, 2835.29, encompasses "other" phosphates not specifically enumerated under preceding subheadings within 2835.2. It broadly covers inorganic phosphate salts that do not fall into the more defined categories of mono- or disodium phosphates (2835.22), potassium phosphates (2835.24), or various calcium phosphates (2835.25 and 2835.26). The key distinction lies in the metallic cation bonded to the phosphate radical, where these "other" phosphates represent a residual classification for a wide array of phosphate salts.

The purpose of this residual category is to ensure comprehensive classification of all inorganic phosphate salts. While siblings address common sodium, potassium, and calcium forms, this heading captures phosphates of less frequently encountered or more specialized cations. This approach prevents the omission of qualifying phosphate compounds from the tariff schedule.

The subcategories within 2835.29 further refine the classification of these "other" phosphates. They distinguish based on the specific cation, such as aluminum phosphates (2835.29.10), triammonium phosphates (2835.29.20), and trisodium phosphates (2835.29.30). The final subheading, 2835.29.51, serves as a further residual for any remaining phosphate salts not accounted for by the preceding specific cation classifications.