HS 251810 Dolomite, not calcined or sintered

Quick Answer: HS Code 251810 covers natural dolomite that has not undergone calcination (heating to remove carbon dioxide) or sintering (heating to fuse particles). This includes crude, crushed, or ground dolomite in its raw state. Dolomite is a common mineral used in construction, agriculture (soil conditioner), glass manufacturing, and as a flux in metallurgy. For importers and exporters, a significant advantage is the consistent duty-free status across major markets. The UK Trade Tariff, EU TARIC, and the US Harmonitic Tariff Schedule all list a 0.00% ad valorem duty rate, or "Free," for products classified under 251810. This simplifies trade compliance and cost forecasting for businesses dealing in uncalcined or unsintered dolomite.

What Are the Import Duty Rates?

🇬🇧 United Kingdom

Code MFN Preferential Unit
2518100000 0.00 % — —

🇪🇺 European Union (TARIC)

Code MFN Preferential Unit
2518100000 0.00 % — —

🇺🇸 United States (HTSUS)

Code MFN Preferential Unit
2518100000 Free — ["t"]

Duty rates sourced from the USITC (US International Trade Commission) Harmonized Tariff Schedule (HTS) (accessed 2/22/2026), EU TARIC – DG TAXUD (Directorate-General for Taxation and Customs Union) (accessed 2/22/2026), and UK Trade Tariff – HMRC (His Majesty's Revenue and Customs) (accessed 2/22/2026).

Data compiled and presented by HSRates.

How Has Trade Volume Developed?

How to Classify This HS Code?

What products does HS 251810 cover?

This subheading covers natural dolomite in its unworked state, specifically not calcined (heated to remove carbon dioxide) or sintered (heated to a point just below melting to form a coherent mass). Dolomite is a common rock-forming mineral, a double carbonate of calcium and magnesium (CaMg(CO₃)₂), and is typically found in sedimentary rock formations. The scope encompasses crude, crushed, or ground dolomite, provided it has not undergone any thermal processing that alters its chemical or physical structure beyond simple comminution. This aligns with the World Customs Organization's Harmonized System Explanatory Notes for Heading 2518, which specifies "Dolomite, whether or not roughly trimmed or merely cut, by sawing or otherwise, into blocks or slabs of a rectangular (including square) shape."

What falls outside HS 251810?

The following products are excluded from HS 251810: calcined dolomite, which is classified under HS 251820, and sintered dolomite, also classified under HS 251820. Furthermore, dolomite that has been processed beyond simple crushing or grinding, such as being cut into specific shapes for building or monumental purposes, would typically fall under Chapter 68, specifically headings like 6802. Magnesian limestone, which contains less than 90% dolomite and more than 10% calcite, is generally classified under HS 2521 as other calcareous stone, not under dolomite. Chemically pure calcium magnesium carbonate, if obtained through synthesis, would also be excluded, as Chapter 25 covers natural mineral products.

What are common classification mistakes for HS 251810?

A common error is misclassifying dolomite that has undergone thermal processing, such as calcination or sintering, under HS 251810. Importers sometimes overlook the "not calcined or sintered" qualifier, leading to incorrect classification of processed dolomite, which properly belongs in HS 251820. Another frequent mistake involves confusing magnesian limestone with true dolomite; the precise chemical composition is critical, as magnesian limestone has a lower dolomite content and is classified elsewhere. Failure to apply General Interpretative Rule (GRI) 1, which states that classification shall be determined according to the terms of the headings and any relative section or chapter notes, often leads to these errors, particularly regarding the specific processing exclusions.

How should importers classify products under HS 251810?

The correct procedure for classifying products under HS 251810 involves a meticulous review of the product's processing and chemical composition. Importers and customs brokers must first confirm that the dolomite is in its natural state and has not undergone any calcination or sintering, which would shift it to HS 251820. A certificate of analysis or a detailed production process description from the supplier is crucial to verify the absence of thermal treatment. Furthermore, it is essential to ensure the material meets the compositional requirements for dolomite, distinguishing it from magnesian limestone or other calcareous stones. Consulting the USITC Harmonized Tariff Schedule (HTS) General Notes and Chapter 25 Explanatory Notes, along with any relevant binding rulings, provides authoritative guidance for accurate classification.

Which HS Codes Are Related?

HS 251820 HS 251910 HS 252310 HS 251710 HS 251310 HS 252210

Not the right code? Search all HS codes to find the correct tariff classification.

FAQ

What is the import duty rate for HS code 2518.10 (Dolomite, not calcined or sintered) in major markets?

For HS code 2518.10, the Most Favored Nation (MFN) duty rates are generally 0.00% ad valorem in many major importing countries. Specifically:

  • United States (HTSUS 2518.10.0000): Free (0.00% ad valorem) as per the U.S. International Trade Commission (USITC) Harmonized Tariff Schedule.
  • European Union (TARIC 2518 10 00 00): 0.00% ad valorem, as per the EU TARIC database.
  • United Kingdom (UK Trade Tariff 2518 10 00 00): 0.00% ad valorem, as per the UK Trade Tariff.

Importers should always verify the current rates with the official tariff schedule of the specific importing country, as rates can be subject to change.

What are the key classification criteria for dolomite under HS 2518.10?

HS code 2518.10 specifically covers 'Dolomite, not calcined or sintered.' The primary classification criteria are:

  1. Mineralogical Identity: The product must be dolomite, which is a carbonate mineral composed of calcium magnesium carbonate (CaMg(CO₃)₂).
  2. Processing State: Crucially, the dolomite must be in its natural state, or merely crushed, ground, or powdered. It must not have undergone calcination (heating to high temperatures to remove carbon dioxide and convert it to calcium magnesium oxide) or sintering (heating to just below the melting point to form a solid mass). If calcined or sintered, it would fall under HS 2518.20 or other relevant headings.
Are there any specific documentation requirements for importing dolomite under HS 2518.10?

Standard import documentation generally applies to HS 2518.10. Importers should be prepared to provide:

  • Commercial Invoice: Detailing the goods, value, seller, and buyer.
  • Packing List: Itemizing the contents of each package.
  • Bill of Lading or Air Waybill: Transport document.
  • Certificate of Origin: While the MFN duty rate is often 0.00%, a Certificate of Origin (e.g., EUR.1, NAFTA/USMCA Certificate, or a general Certificate of Origin) may still be required for statistical purposes, to claim preferential treatment under certain trade agreements (even if the MFN rate is free), or to comply with specific import regulations of the destination country. For example, under USMCA, while the duty is free, a certification of origin may still be requested by CBP.
  • Material Safety Data Sheet (MSDS) or Safety Data Sheet (SDS): May be requested by customs or port authorities for certain bulk mineral shipments, depending on national regulations, to ensure safe handling and transport.

Importers should consult the specific customs regulations of the importing country for any additional or unique requirements.

How do common trade agreements affect the import of dolomite under HS 2518.10?

Given that the Most Favored Nation (MFN) duty rate for HS 2518.10 is frequently 0.00% ad valorem in many countries, the practical impact of preferential trade agreements on the duty rate itself is often minimal or non-existent, as there is no duty to reduce further. For example:

  • USMCA (United States-Mexico-Canada Agreement): Dolomite originating from Mexico or Canada and imported into the U.S. (or vice versa) would be duty-free, consistent with the MFN rate. However, a USMCA certification of origin would still be required to formally claim this preferential treatment and demonstrate compliance with the agreement's rules of origin.
  • EU Free Trade Agreements (FTAs): For imports into the EU from FTA partner countries (e.g., Japan, South Korea, Canada), dolomite under HS 2518 10 00 would also be duty-free, aligning with the EU's MFN rate.

While the duty rate may not change, trade agreements can still be relevant for:

  • Rules of Origin: Determining if the product genuinely originates from a partner country.
  • Non-Tariff Barriers: Addressing potential non-tariff measures or facilitating customs procedures.
  • Statistical Reporting: Proper declaration under the agreement may still be required for trade statistics.

Importers should always ensure their goods meet the rules of origin of any claimed trade agreement, even if the duty rate is already zero.