HS code · 6-digit subheading
HS Code 2831.90 – Dithionites and sulphoxylates; other than sodium
HS code 2831.90 is the 6-digit subheading for dithionites and sulphoxylates, other than sodium. It is used for zinc dithionite, calcium dithionite, magnesium dithionite, potassium dithionite and zinc formaldehyde sulphoxylate.
What HS 2831.90 covers
This HS code covers dithionites and sulphoxylates of elements other than sodium, such as zinc dithionite or calcium dithionite. While less common than their sodium counterparts, these compounds serve specialized roles as reducing agents in niche industrial applications. Their uses include certain textile processes, photographic chemicals, and as catalysts or stabilizers in specific chemical reactions where a non-sodium reducing agent is preferred or required. Importers are typically countries with specialized chemical industries or those requiring specific reducing agents for unique manufacturing processes, often in smaller volumes compared to sodium variants. Exporters are usually specialized chemical manufacturers in countries like Germany, Japan, and the USA, capable of producing these less common but critical compounds. Key trade considerations involve ensuring high purity for specific applications, safe handling and storage due to their reactive nature, and adherence to chemical safety regulations. The market for these chemicals is highly specialized and demand-driven.
- Covers
- Zinc dithionite
- Calcium dithionite
- Magnesium dithionite
- Potassium dithionite
- Zinc formaldehyde sulphoxylate
- Calcium formaldehyde sulphoxylate
- Examples
- 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. This code is distinct from sodium dithionites and sulphoxylates (283110) and can be confused with other sulfur-containing reducing agents if not precisely identified by their metallic component.
Top exporters and importers of HS code 283190, 2025
In 2025, the largest exporter of HS code 283190 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.
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 2831.90 2
Brazil splits HS 2831.90 into 2 NCM codes, Mercosur's 8-digit tariff lines.
All Brazil NCM codes in heading 28.31 →
Source: Siscomex NCM table, updated Oct 2026. The Portuguese text is official; the English is our translation.
Questions about HS 2831.90
What is HS code 283190?
HS code 283190 is a 6-digit subheading in the Harmonized System that covers: Dithionites and sulphoxylates; other than sodium. This HS code covers dithionites and sulphoxylates of elements other than sodium, such as zinc dithionite or calcium dithionite. While less common than their sodium counterparts, these compounds serve specialized roles as reducing agents in niche industrial applications. Their uses include certain textile processes, photographic chemicals, and as catalysts or stabilizers in specific chemical reactions where a non-sodium reducing agent is preferred or required. Importers are typically countries with specialized chemical industries or those requiring specific reducing agents for unique manufacturing processes, often in smaller volumes compared to sodium variants. Exporters are usually specialized chemical manufacturers in countries like Germany, Japan, and the USA, capable of producing these less common but critical compounds. Key trade considerations involve ensuring high purity for specific applications, safe handling and storage due to their reactive nature, and adherence to chemical safety regulations. The market for these chemicals is highly specialized and demand-driven.
What products fall under HS code 283190?
Zinc dithionite, Calcium dithionite, Magnesium dithionite, Potassium dithionite, Zinc formaldehyde sulphoxylate, Calcium formaldehyde sulphoxylate
What are common misclassifications for HS code 283190?
This code is distinct from sodium dithionites and sulphoxylates (283110) and can be confused with other sulfur-containing reducing agents if not precisely identified by their metallic component.
Which countries are the top exporters of goods under HS code 283190?
In 2025, the top exporters of HS code 283190 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 goods under HS code 283190?
In 2025, the top importers of HS code 283190 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.
How is HS code 283190 structured?
HS code 283190 is a 6-digit subheading under the Harmonized System. The first 2 digits (28) identify the chapter, digits 3-4 (31) identify the heading, and digits 5-6 (90) specify the subheading. This code is standardized globally by the World Customs Organization.
What is the Brazil NCM code for HS code 283190?
Brazil splits HS code 283190 into 2 NCM codes: 2831.90.10 (Zinc dithionite), 2831.90.90 (Other dithionites and sulphoxylates). The first 6 digits of each match the HS code.