2508.40.01.20 - Decolorizing earths and fuller's earth

This HTS category encompasses "decolorizing earths and fuller's earth." These are natural clays known for their absorbent properties, primarily used for their ability to remove color, odor, and impurities from liquids such as oils, fats, and petroleum products. Their effectiveness stems from their unique mineral composition, typically dominated by montmorillonite or other smectite clays, which possess a high surface area and cation exchange capacity.

This classification is distinct from its sibling categories within 2508.40.01. Specifically, it is differentiated from "Common blue clay and other ball clays" (2508.40.01.10), which are generally plastic clays used in ceramics, and "Other" (2508.40.01.50), which would include clays not otherwise specified within this heading but still falling under the broader "Other clays" umbrella. The defining characteristic here is the intended application as a decolorizing agent.

As a leaf node, this category does not have further subcategories. Therefore, classification within 2508.40.01.20 relies on the inherent properties and intended use of the material. Key classification criteria will include mineralogical analysis confirming the presence of decolorizing clays and evidence of their application in purification processes, distinguishing them from other types of clays that may share similar mineral structures but lack the specific absorbent and adsorptive qualities for decolorization.