Product classification
HS code for Sodium dithionite: 2831.10
Dithionites and sulphoxylates, of sodium.
Classification of sodium dithionite under HS 2831.10
Sodium dithionite, also known as sodium hydrosulphite, is classified under HS code 2831.10. This classification is situated within Chapter 28, which covers inorganic chemicals, precious metals, rare-earth metals, radioactive elements, or isotopes. Heading 2831 is specifically designated for dithionites and sulphoxylates. Within this heading, the single-dash subheading 2831.10 is reserved for those of sodium. Sodium dithionite is a powerful reducing agent used extensively in the textile industry for vat dyeing and in the pulp and paper industry for bleaching. The classification is determined by GRI 1, based on the chemical identity of the substance. Even if the sodium dithionite is stabilized with other chemicals to prevent spontaneous combustion or decomposition, it remains classified under 2831.10, provided it retains its character as a separate chemically defined compound as per the notes to Chapter 28.
- Covers
- Sodium dithionite (Sodium hydrosulphite)
- Stabilized sodium dithionite
- Sodium dithionite in powder or granular form
- Technical grade sodium dithionite
- Also under 2831.10
- BASF Sodium Dithionite
- Arkema Sodium Dithionite
- Sigma-Aldrich Sodium Formaldehyde Sulphoxylate
- Huntsman Textile Effects Dithionite
Codes often confused with 2831.10
Common mistake. Sodium dithionite is frequently confused with sodium sulphite (HS code 2832.10) or sodium metabisulphite (HS code 2832.20). While these chemicals are related and often used in similar industrial processes, they are chemically distinct salts of different sulfur-containing acids. Another potential misclassification is 2833.11 (disodium sulphate), which is a much more stable and common salt. It is vital to distinguish between dithionites (2831) and sulphites/thiosulphates (2832) to ensure regulatory compliance, especially since sodium dithionite is often regulated as a hazardous material (Class 4.2) for transport.
Top exporters and importers of HS 283110 (the code used for sodium dithionite), 2025
In 2025, the largest exporter of HS 283110 (the code used for sodium dithionite) in UN Comtrade data was China, with 54% of world exports; the largest importer in UN Comtrade data was Türkiye, with 12% 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 283110, not only sodium dithionite.
Top exporters 2025 · share of world exports
- 1 China $96M 54% of world exports
- 2 India $36M 20% of world exports
- 3 Belgium $28M 16% of world exports
World total: $178M Reported figures on UN Comtrade ↗
Top importers 2025 · share of world imports
- 1 Türkiye $29M 12% of world imports
- 2 Vietnam* ~$19M 7.9% of world imports · partner records ↗
- 3 United States $14M 5.8% of world imports
World total: $239M 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 sodium dithionite
Brazil splits HS 2831.10 into 4 NCM codes. Pick the one that matches your product:
- 2831.10.11Stabilised sodium dithionite
- 2831.10.19Other sodium dithionites
- 2831.10.21Sodium formaldehyde sulphoxylate
- 2831.10.29Other sodium sulphoxylates
Source: Siscomex NCM table, updated Oct 2026. The Portuguese text on each NCM page is the official one.
Questions about sodium dithionite
What is the HS code for Sodium dithionite?
The HS code for Sodium dithionite is 283110 (Dithionites and sulphoxylates; of sodium). The HS code for sodium dithionite is 2831.10, which covers dithionites and sulphoxylates of sodium.
How do I classify Sodium dithionite for customs?
Sodium dithionite is classified under HS code 283110 — Dithionites and sulphoxylates; of sodium. This is a 6-digit subheading level code.
Is sodium hydrosulphite the same as sodium dithionite in the HS system?
Yes, sodium hydrosulphite is a common commercial name for sodium dithionite, and both are classified under HS code 2831.10.
Which countries are the top exporters of sodium dithionite (HS 283110)?
In 2025, the top exporters of HS 283110 (the code used for sodium dithionite) in UN Comtrade data were China ($96M, 54% of world exports), India ($36M) and Belgium ($28M). World exports came to about $178M, 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 sodium dithionite (HS 283110)?
In 2025, the top importers of HS 283110 (the code used for sodium dithionite) in UN Comtrade data were Türkiye ($29M, 12% of world imports), Vietnam (about $19M) and the United States ($14M). World imports came to about $239M, 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 Sodium dithionite the same in all countries?
The base HS code 283110 for Sodium 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 sodium dithionite in Brazil?
Brazil splits HS 283110 into 4 NCM codes, so the right one for sodium dithionite depends on the product's details: 2831.10.11 (Stabilised sodium dithionite), 2831.10.19 (Other sodium dithionites), 2831.10.21 (Sodium formaldehyde sulphoxylate), 2831.10.29 (Other sodium sulphoxylates).