HS Code 25.12 – Siliceous fossil meals (e.g. kieselguhr, tripolite and diatomite) and similar siliceous earths; whether or not calcined, of an apparent specific gravity of 1 or less

HS code 2512 is a 4-digit heading in the Harmonized System that covers: Siliceous fossil meals (e.g. kieselguhr, tripolite and diatomite) and similar siliceous earths; whether or not calcined, of an apparent specific gravity of 1 or less. Heading 2512 encompasses various siliceous fossil meals and similar siliceous earths, most notably kieselguhr (diatomaceous earth), tripolite, and diatomite. These naturally occurring, finely porous sedimentary rocks are primarily composed of the fossilized remains of diatoms, which are microscopic algae. The critical defining characteristic for classification under this heading is an "apparent specific gravity of 1 or less," indicating their lightweight, porous nature. This heading includes these materials whether they are uncalcined (raw) or calcined (heat-treated to remove organic impurities and improve filtration properties), provided they retain their fundamental character. In international trade, these materials are highly valued for their unique properties: high porosity, low density, large surface area, and abrasive qualities. They serve as essential filter aids in numerous industries (beverages, pharmaceuticals, chemicals), as absorbents (e.g., in cat litter, oil spills), mild abrasives (polishing compounds), functional fillers (paints, plastics, rubber), and even as inert carriers for pesticides or animal feed additives. The scope of 2512 is limited to these specific siliceous earths in their raw or merely calcined forms. Further processing, such as agglomeration, mixing with other materials to form specific products (e.g., prepared filtering media with binders), or shaping into articles, would typically lead to classification elsewhere, often in Chapter 68. Accurate classification under 2512 is crucial for trade compliance, as it impacts applicable duties, taxes, and regulatory requirements, particularly concerning food-grade or industrial-grade distinctions. Historically, diatomaceous earth has been used for centuries, but its industrial applications expanded significantly in the 19th and 20th centuries, especially in filtration. This heading falls within Section V (Mineral Products) and Chapter 25 (Salt; Sulphur; Earths and Stone; Plastering Materials, Lime and Cement), which generally covers mineral products in their crude or primary processed forms, emphasizing their natural origin and minimal alteration.

Diatomaceous earth filter aids, uncalcined kieselguhr, calcined diatomite, tripolite abrasive powder, food-grade diatomaceous earth, industrial-grade diatomaceous earth, DE for pool filters, DE for pest control, DE absorbents for spills, DE as animal feed additive, DE as a filler for paints, DE for rubber manufacturing, DE for plastic production, DE for paper manufacturing, naturally occurring siliceous earths for filtration, kieselguhr for beverage clarification, tripolite for polishing compounds, diatomite for insulation, raw diatomaceous earth, flux-calcined diatomite, natural kieselguhr, diatomite powder, uncalcined tripolite, processed diatomite (not aggregated).

Common misclassification mistakes often arise from the processing level or intended use. Traders might confuse 2512 with heading 6815 if the siliceous earths are agglomerated or mixed with other materials to form prepared filtering media, rather than being merely calcined. Another error is classifying them under other mineral fillers like kaolin (2507) or other common earths (2508) if the specific 'fossil meal' and 'apparent specific gravity of 1 or less' characteristics are overlooked. It's crucial to confirm the material's natural origin, minimal processing (calcining is allowed), and the specific gravity to avoid incorrect duties or regulatory scrutiny.

In 2025, the top exporters of HS code 2512 in UN Comtrade data were the United States ($54M, 31% of world exports), Germany ($28M) and France ($19M). World exports came to about $178M, adding countries' reported figures and partner-based estimates for those that did not report (UN Comtrade data). Countries that did not report 2025 data are estimated from partner records, which can understate them.

In 2025, the top importers of HS code 2512 in UN Comtrade data were Germany ($20M, 8.0% of world imports), Italy ($20M) and Brazil ($19M). World imports came to about $250M, adding countries' reported figures and partner-based estimates for those that did not report (UN Comtrade data). Countries that did not report 2025 data are estimated from partner records, which can understate them.

HS code 2512 is a 4-digit heading under Chapter 25 of the Harmonized System. The first 2 digits (25) identify the chapter, and digits 3-4 (12) specify the heading. This code contains multiple 6-digit subheadings for precise product classification.