2839.90.50.00 - Other

This HTS category, 2839.90.50.00, encompasses "Other" silicates and commercial alkali metal silicates that do not fall under more specific classifications. Within the broader heading of silicates (2839), this subcategory serves as a residual category for alkali metal silicates not explicitly defined elsewhere. This generally includes various forms of alkali metal silicates that may not be specifically identified by their parent alkali metal element.

Distinguishing this category from its sibling, 2839.90.10.00 ("Of potassium"), is crucial. While the sibling category is exclusively for silicates where potassium is the primary alkali metal component, this "Other" category would cover silicates of other alkali metals, such as sodium or lithium, if they are not otherwise specified, or complex alkali metal silicates where a specific alkali metal is not the sole defining characteristic for a more precise classification.

As this classification represents a leaf node within the HTS, there are no further subcategories. Therefore, the classification of goods under 2839.90.50.00 relies heavily on the principle of elimination. Importers and customs brokers must first exhaust all more specific silicate classifications (e.g., potassium silicates) before considering this residual category. The classification will depend on the chemical composition and the absence of a more precise tariff provision.