Product classification
HS code for Dead-burned magnesia: 2519.90
Magnesia, fused or dead-burned (sintered), whether or not containing small quantities of other oxides added before sintering, other magnesium oxide, whether or not pure, (not natural magnesium carbonate).
Classification of dead-burned magnesia under HS 2519.90
Dead-burned magnesia is classified under HS code 2519.90. This classification covers magnesium oxide that has been heated to very high temperatures (sintered) to render it chemically inactive and resistant to moisture. This process, known as "dead-burning," makes the material suitable for refractory applications, such as lining furnaces and kilns. The HS code 2519.90 includes both fused magnesia and dead-burned (sintered) magnesia. It is classified in Chapter 25, which covers salt, sulfur, earths, and stone, because it is considered a mineral product that has undergone thermal treatment without changing its fundamental mineral identity into a chemically pure compound. Even if small quantities of other oxides (like iron or aluminum) are added before sintering to facilitate the process, the product remains under 2519.90. The classification is driven by the industrial nature of the product as a refractory raw material rather than a laboratory-grade chemical.
- Covers
- Sintered magnesia (dead-burned)
- Fused magnesia
- Refractory grade magnesium oxide
- Clinkered magnesia
- Magnesia with small amounts of added oxides for sintering
- Also under 2519.90
- RHI Magnesita Fused Magnesia
- Vesuvius Dead-Burned Magnesia
- Magnezit Group Sintered Magnesia
- Martin Marietta Magnesia Specialties
Codes often confused with 2519.90
Common mistake. Dead-burned magnesia is frequently confused with HS code 2519.10, which is for natural magnesium carbonate (magnesite) that has not been processed. Another common misclassification is HS code 2825.90, which covers chemically pure magnesium oxide. The distinction lies in the purity and the intended use; 2519.90 is for industrial/refractory grades, while 2825.90 is for purified chemical compounds. Light-burned or caustic-calcined magnesia, which is processed at lower temperatures and remains chemically reactive, is also classified under 2519.90 but must be distinguished from the dead-burned variety in commercial invoices.
Top exporters and importers of HS 251990 (the code used for dead-burned magnesia), 2025
In 2025, the largest exporter of HS 251990 (the code used for dead-burned magnesia) in UN Comtrade data was China, with 47% of world exports; the largest importer in UN Comtrade data was the United States, with 13% of world imports. Countries that did not report 2025 data are estimated from partner records, which can understate them.
Figures cover everything classified under HS 251990, not only dead-burned magnesia.
Top exporters 2025 · share of world exports
- 1 China $860M 47% of world exports
- 2 Netherlands $142M 7.9% of world exports
- 3 Brazil $99M 5.5% of world exports
World total: $1.8B Reported figures on UN Comtrade ↗
Top importers 2025 · share of world imports
- 1 United States $266M 13% of world imports
- 2 India $193M 9.2% of world imports
- 3 Germany $183M 8.7% of world imports
World total: $2.1B Reported figures on UN Comtrade ↗
How these figures are built
109 countries reported 2025 trade to UN Comtrade in HS 2022, and their own totals are used. Countries that did not report are estimated from what other countries recorded trading with them. Those estimates miss trade with other non-reporting countries, so they can be low, and a non-reporting country can rank higher than shown or be missing from the list. World totals add both and leave out trade between two non-reporting countries. Figures are in current US dollars; reported imports are mostly valued CIF and exports FOB, and exports include re-exports. The UN Comtrade links show the underlying records; they can also list a few reporters left out here (regional groups and older HS editions).
Source: UN Comtrade (United Nations Statistics Division), 2025 annual data.
Brazil NCM codes for dead-burned magnesia
Brazil splits HS 2519.90 into 2 NCM codes. Pick the one that matches your product:
- 2519.90.10Fused (electrofused) magnesia
- 2519.90.90Dead-burned magnesia and other magnesium oxide
Source: Siscomex NCM table, updated Oct 2026. The Portuguese text on each NCM page is the official one.
Questions about dead-burned magnesia
What is the HS code for Dead-burned magnesia?
The HS code for Dead-burned magnesia is 251990 (Magnesia, fused or dead-burned (sintered); whether or not containing small quantities of other oxides added before sintering, other magnesium oxide, whether or not pure, (not natural magnesium carbonate)). The HS code for dead-burned (sintered) magnesia is 2519.90.
How do I classify Dead-burned magnesia for customs?
Dead-burned magnesia is classified under HS code 251990 — Magnesia, fused or dead-burned (sintered); whether or not containing small quantities of other oxides added before sintering, other magnesium oxide, whether or not pure, (not natural magnesium carbonate). This is a 6-digit subheading level code.
Is dead-burned magnesia considered a chemical?
No, for customs purposes, it is classified as a mineral product under Chapter 25, provided it is not chemically pure.
Which countries are the top exporters of dead-burned magnesia (HS 251990)?
In 2025, the top exporters of HS 251990 (the code used for dead-burned magnesia) in UN Comtrade data were China ($860M, 47% of world exports), the Netherlands ($142M) and Brazil ($99M). World exports came to about $1.8B, 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.
Which countries are the top importers of dead-burned magnesia (HS 251990)?
In 2025, the top importers of HS 251990 (the code used for dead-burned magnesia) in UN Comtrade data were the United States ($266M, 13% of world imports), India ($193M) and Germany ($183M). World imports came to about $2.1B, 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.
Is the HS code for Dead-burned magnesia the same in all countries?
The base HS code 251990 for Dead-burned magnesia is internationally standardized for the first 6 digits across 200+ countries. Individual countries may add additional digits for national tariff lines and specific classifications.
What is the NCM code for dead-burned magnesia in Brazil?
Brazil splits HS 251990 into 2 NCM codes, so the right one for dead-burned magnesia depends on the product's details: 2519.90.10 (Fused (electrofused) magnesia), 2519.90.90 (Dead-burned magnesia and other magnesium oxide).