2620.21.00 - Leaded gasoline sludges and leaded anti-knock compound sludges

This HTS category, 2620.21.00, specifically covers sludges derived from leaded gasoline and leaded anti-knock compounds. These are residual materials, typically generated during the refining or processing of fuels, that contain significant quantities of lead or lead compounds. The focus is on the direct byproducts of the anti-knock additive processes in gasoline.

This classification distinguishes itself from its sibling, 2620.29.00, by its exclusive focus on leaded gasoline and anti-knock compound sludges. Category 2620.29.00, conversely, encompasses all other residues containing arsenic, metals, or their compounds that are not specifically categorized elsewhere within the 2620 heading and do not primarily consist of lead.

The subcategories under 2620.21.00 allow for further granular classification based on the presence of specific metallic elements. These include subdivisions for copper content (2620.21.00.10), lead content (2620.21.00.20), zinc content (2620.21.00.30), silver content (2620.21.00.40), and gold content (2620.21.00.50). This detailed breakdown is crucial for accurate reporting, duty assessment, and potential recovery of valuable metals from these industrial residues.