Product classification
HS code for Potassium silicate: 2839.90
Silicates, commercial alkali metal silicates, other than of sodium.
Classification of potassium silicate under HS 2839.90
Potassium silicate is classified under HS code 2839.90, which falls within Chapter 28 of the Harmonized System. This chapter is dedicated to inorganic chemicals, including precious metals, rare-earth metals, and radioactive elements. Heading 2839 specifically covers silicates and commercial alkali metal silicates. While sodium silicates are explicitly partitioned into subheadings 2839.11 and 2839.19, potassium silicate is categorized under the "Other" subheading, 2839.90. The classification is determined by the chemical composition of the substance, which consists of varying ratios of silicon dioxide and potassium oxide. These compounds are typically produced by fusing high-purity silica sand with potassium carbonate or potassium hydroxide at high temperatures. The resulting product can be in solid form (glass) or dissolved in water to create a liquid solution. Under the General Rules of Interpretation (GRI) 1 and 6, the specific chemical identity dictates its placement here rather than in prepared chemical mixtures of Chapter 38, provided it is a separate chemically defined compound. The classification remains consistent regardless of whether the product is in anhydrous form or aqueous solution, as long as it maintains its identity as a commercial alkali metal silicate.
- Covers
- Potassium metasilicate
- Potassium orthosilicate
- Aqueous solutions of potassium silicate
- Anhydrous potassium silicate glass
- Liquid potassium water glass
- Also under 2839.90
PQ Corporation Kasil, W. R. Grace & Co. Lithium Silicate, Evonik Potassium Silicate, Huber Engineered Materials Potassium Silicate
Codes often confused with 2839.90
Common mistake. Potassium silicate is frequently confused with sodium silicates, which are classified under 2839.11 or 2839.19. Another common error involves classifying prepared binders for foundry molds or anti-corrosive preparations containing potassium silicate under heading 3824. If the product is a simple solution of potassium silicate in water, it must remain in 2839.90. However, if it contains added pigments or other functional additives, it may move to Chapter 32 (paints) or Chapter 38 (miscellaneous chemicals).
Top exporters and importers of HS 283990 (the code used for potassium silicate), 2025
In 2025, the largest exporter of HS 283990 (the code used for potassium silicate) in UN Comtrade data was the United States, with 25% of world exports; the largest importer in UN Comtrade data was Canada, with 9.1% 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 283990, not only potassium silicate.
Top exporters 2025 · share of world exports
- 1 United States $72M 25% of world exports
- 2 China $57M 20% of world exports
- 3 Netherlands $34M 12% of world exports
World total: $289M Reported figures on UN Comtrade ↗
Top importers 2025 · share of world imports
- 1 Canada $32M 9.1% of world imports
- 2 Saudi Arabia $27M 7.6% of world imports
- 3 China $24M 6.8% of world imports
World total: $351M 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 potassium silicate
Brazil splits HS 2839.90 into 6 NCM codes. Pick the one that matches your product:
- 2839.90.10Magnesium silicate
- 2839.90.20Aluminium silicate
- 2839.90.30Zirconium silicate
- 2839.90.40Lead silicate
- 2839.90.50Potassium silicate
- 2839.90.90Other silicates
Source: Siscomex NCM table, updated Oct 2026. The Portuguese text on each NCM page is the official one.
Questions about potassium silicate
What is the HS code for Potassium silicate?
The HS code for Potassium silicate is 283990 (Silicates; commercial alkali metal silicates, other than of sodium). The HS code for potassium silicate is 2839.90, which covers alkali metal silicates other than those of sodium.
How do I classify Potassium silicate for customs?
Potassium silicate is classified under HS code 283990 — Silicates; commercial alkali metal silicates, other than of sodium. This is a 6-digit subheading level code.
Is potassium silicate classified differently if it is a liquid?
No, both the solid (lump) form and the aqueous solution are classified under 2839.90, provided no other substances have been added to change its essential character.
Which countries are the top exporters of potassium silicate (HS 283990)?
In 2025, the top exporters of HS 283990 (the code used for potassium silicate) in UN Comtrade data were the United States ($72M, 25% of world exports), China ($57M) and the Netherlands ($34M). World exports came to about $289M, 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 potassium silicate (HS 283990)?
In 2025, the top importers of HS 283990 (the code used for potassium silicate) in UN Comtrade data were Canada ($32M, 9.1% of world imports), Saudi Arabia ($27M) and China ($24M). World imports came to about $351M, 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 Potassium silicate the same in all countries?
The base HS code 283990 for Potassium silicate 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 potassium silicate in Brazil?
Brazil splits HS 283990 into 6 NCM codes, so the right one for potassium silicate depends on the product's details: 2839.90.10 (Magnesium silicate), 2839.90.20 (Aluminium silicate), 2839.90.30 (Zirconium silicate), 2839.90.40 (Lead silicate), 2839.90.50 (Potassium silicate), 2839.90.90 (Other silicates).