2853.90 - Other:

This HTS category, 2853.90, encompasses "Other" inorganic chemical compounds that do not fit into the more specific subheadings within heading 2853. This primarily includes phosphides, provided they are not ferrophosphorous and are chemically defined. It also covers a range of other inorganic substances such as distilled or conductivity water, water of similar purity, liquid air (regardless of whether rare gases have been removed), compressed air, and amalgams, excluding those composed of precious metals.

It is important to distinguish this broad category from its sibling, 2853.10.00.00, which specifically covers cyanogen chloride. While both fall under heading 2853, 2853.10.00.00 is for a single, defined chemical, whereas 2853.90.00.00 serves as a residual category for a variety of other inorganic compounds not otherwise specified. The mention of "I. HYDROCARBONS AND THEIR HALOGENATED, SULFONATED, NITRATED OR NITROSATED DERIVATIVES" as a sibling is likely a misplaced reference or an example of a different chapter's scope, and does not directly inform the classification within 2853.

Within the 2853.90.00.00 heading, further subclassification is provided. The subcategory "Phosphides, whether or not chemically defined, excluding ferrophosphorous" represents a specific group of items that could otherwise fall under the general "Other" description. The remaining subcategory, 2853.90.90, serves as a further residual for any remaining inorganic compounds, purified water, compressed air, or amalgams that do not meet the criteria for phosphides and are not specifically listed elsewhere.