Product classification
HS code for Magnesium oxide: 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 magnesium oxide under HS 2519.90
Magnesium oxide is classified under HS code 2519.90, which encompasses magnesia that has been processed through fusion or sintering. This code is situated within Chapter 25, covering salt, sulfur, earths, and stone, rather than the chemical chapter, because it refers to mineral-based products. The classification includes fused magnesia, which is produced in electric arc furnaces to achieve high purity and crystal size, and dead-burned (sintered) magnesia, which is fired at extremely high temperatures to make it chemically inert for refractory use. The HS code 2519.90 is specifically for 'other' magnesium oxides that are not natural magnesium carbonate (magnesite). The determination for this code relies on the thermal treatment the mineral has undergone and its intended use in industrial applications like furnace linings or cement production.
- Covers
- Fused magnesia
- Dead-burned (sintered) magnesia
- Caustic calcined magnesia
- Heavy magnesium oxide
- Light magnesium oxide (non-pharmaceutical)
- 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. Magnesium oxide is often misclassified under HS code 2519.10, which is strictly for natural magnesium carbonate (magnesite). It is also frequently confused with HS code 2816.10, which covers magnesium hydroxide and peroxide. While 2816.10 is for chemically defined inorganic compounds, 2519.90 is for mineral-derived oxides. Furthermore, high-purity pharmaceutical grade magnesium oxide might sometimes be incorrectly placed in Chapter 30.
Top exporters and importers of HS 251990 (the code used for magnesium oxide), 2025
In 2025, the largest exporter of HS 251990 (the code used for magnesium oxide) 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 magnesium oxide.
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 magnesium oxide
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 magnesium oxide
What is the HS code for Magnesium oxide?
The HS code for Magnesium oxide 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 standard HS code for processed magnesium oxide (fused or dead-burned) is 2519.90.
How do I classify Magnesium oxide for customs?
Magnesium oxide 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 caustic calcined magnesia under the same code?
Yes, caustic calcined magnesia is generally classified under 2519.90 as it is a form of processed magnesium oxide.
Which countries are the top exporters of magnesium oxide (HS 251990)?
In 2025, the top exporters of HS 251990 (the code used for magnesium oxide) 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 magnesium oxide (HS 251990)?
In 2025, the top importers of HS 251990 (the code used for magnesium oxide) 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 Magnesium oxide the same in all countries?
The base HS code 251990 for Magnesium oxide 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 magnesium oxide in Brazil?
Brazil splits HS 251990 into 2 NCM codes, so the right one for magnesium oxide depends on the product's details: 2519.90.10 (Fused (electrofused) magnesia), 2519.90.90 (Dead-burned magnesia and other magnesium oxide).