Product classification
HS code for Zinc dithionite: 2831.90
Dithionites and sulphoxylates, other than sodium.
Classification of zinc dithionite under HS 2831.90
Zinc dithionite is classified under HS code 283190. This code is situated within Chapter 28, which covers inorganic chemicals, precious metal compounds, and isotopes. Specifically, heading 2831 covers dithionites and sulphoxylates. While sodium dithionite is the most common and has its own subheading (283110), all other metal dithionites, including zinc dithionite, are grouped under the 'other' category of 283190. Zinc dithionite (ZnS2O4), also known as zinc hydrosulfite, is a powerful reducing agent. Its classification is based on its chemical identity as a defined inorganic salt. In industrial applications, it is often used for bleaching groundwood paper pulp and textiles. For customs purposes, the product must be a separate chemically defined compound. If the zinc dithionite is mixed with other substances for a specific functional use, such as a prepared dye or a finished laundry detergent, it might be moved to Chapter 32 or 34, but in its pure or stabilized chemical form, 283190 is the correct designation.
- Covers
- Zinc dithionite (Zinc hydrosulfite)
- Zinc sulphoxylate
- Stabilized zinc dithionite powders
- Aqueous solutions of zinc dithionite
- Also under 2831.90
- Sigma-Aldrich Zinc Dithionite
- Alfa Aesar Calcium Dithionite
- TCI Chemicals Zinc Formaldehyde Sulphoxylate
- Merck KGaA Potassium Dithionite
Codes often confused with 2831.90
Common mistake. The most frequent misclassification for zinc dithionite is HS code 283110, which is strictly for sodium dithionite. Because sodium dithionite is more widely traded, it is often used as a default, but this is incorrect for zinc-based compounds. Another common error is classification under 283329 (other sulfates). While they sound similar, dithionites (S2O4) and sulfates (SO4) are chemically distinct salts with different oxidation states and industrial properties. Finally, if the product is used as a pigment, it might be confused with 320649, though 283190 remains correct for the pure chemical substance.
Top exporters and importers of HS 283190 (the code used for zinc dithionite), 2025
In 2025, the largest exporter of HS 283190 (the code used for zinc dithionite) in UN Comtrade data was China, with 70% of world exports; the largest importer in UN Comtrade data was Pakistan, with 41% 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 283190, not only zinc dithionite.
Top exporters 2025 · share of world exports
- 1 China $16M 70% of world exports
- 2 India $3.3M 15% of world exports
- 3 Russia* ~$1.3M 5.8% of world exports · partner records ↗
World total: $22M Reported figures on UN Comtrade ↗
Top importers 2025 · share of world imports
- 1 Pakistan $12M 41% of world imports
- 2 Egypt $6.1M 22% of world imports
- 3 Türkiye $2.0M 7.0% of world imports
World total: $28M 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 marked * did not, so their figures add up what other countries recorded trading with them, and their exports are valued at buyers' CIF prices. 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 zinc dithionite
Brazil splits HS 2831.90 into 2 NCM codes. Pick the one that matches your product:
- 2831.90.10Zinc dithionite
- 2831.90.90Other dithionites and sulphoxylates
Source: Siscomex NCM table, updated Oct 2026. The Portuguese text on each NCM page is the official one.
Questions about zinc dithionite
What is the HS code for Zinc dithionite?
The HS code for Zinc dithionite is 283190 (Dithionites and sulphoxylates; other than sodium). The HS code for zinc dithionite is 283190.
How do I classify Zinc dithionite for customs?
Zinc dithionite is classified under HS code 283190 — Dithionites and sulphoxylates; other than sodium. This is a 6-digit subheading level code.
Is zinc dithionite the same as zinc sulfate?
No, they are different chemicals. Zinc dithionite (283190) is a reducing agent used for bleaching, while zinc sulfate (283329) is commonly used in fertilizers and animal feed.
Which countries are the top exporters of zinc dithionite (HS 283190)?
In 2025, the top exporters of HS 283190 (the code used for zinc dithionite) in UN Comtrade data were China ($16M, 70% of world exports), India ($3.3M) and Russia (about $1.3M). World exports came to about $22M, 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 zinc dithionite (HS 283190)?
In 2025, the top importers of HS 283190 (the code used for zinc dithionite) in UN Comtrade data were Pakistan ($12M, 41% of world imports), Egypt ($6.1M) and Türkiye ($2.0M). World imports came to about $28M, 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 Zinc dithionite the same in all countries?
The base HS code 283190 for Zinc dithionite 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 zinc dithionite in Brazil?
Brazil splits HS 283190 into 2 NCM codes, so the right one for zinc dithionite depends on the product's details: 2831.90.10 (Zinc dithionite), 2831.90.90 (Other dithionites and sulphoxylates).