HS code · 6-digit subheading
HS Code 2837.20 – Complex cyanides
HS code 2837.20 is the 6-digit subheading for complex cyanides. It is used for potassium ferrocyanide, sodium ferrocyanide, potassium ferricyanide, ammonium ferrocyanide and prussian blue pigment (as a complex cyanide derivative).
What HS 2837.20 covers
This HS code specifically covers complex cyanides, which are distinct from simple cyanides due to their coordination compound structure where the cyanide ion acts as a ligand. Key examples include ferrocyanides (e.g., potassium ferrocyanide, sodium ferrocyanide) and ferricyanides (e.g., potassium ferricyanide). Unlike simple cyanides, these compounds are generally much less toxic and have a broader range of industrial applications. Ferrocyanides are widely used as anti-caking agents in road salt and table salt, as food additives (E535, E536), in the production of pigments like Prussian blue, and in electroplating. Ferricyanides are used in photography, blueprinting, and as mild oxidizing agents in organic synthesis. The trade in complex cyanides involves chemical manufacturers, food ingredient suppliers, and specialized industrial users. Importers are often food processing companies, pigment manufacturers, or photographic chemical suppliers. Exporters are typically chemical producers with advanced synthesis capabilities. While less hazardous than simple cyanides, proper handling and quality control are still important, especially for food-grade applications.
- Covers
- Potassium ferrocyanide
- Sodium ferrocyanide
- Potassium ferricyanide
- Ammonium ferrocyanide
- Prussian blue pigment (as a complex cyanide derivative)
- Ferric ferrocyanide
- Examples
- Sigma-Aldrich Potassium Ferrocyanide
- BASF Potassium Ferricyanide
- Merck Sodium Ferrocyanide
Codes often confused with 2837.20
Common mistake. This code is often confused with simple cyanides (283711, 283719) due to the "cyanide" in the name, but their chemical structure and toxicity profiles are vastly different. It's crucial to distinguish between simple ionic cyanides and these coordination complexes.
Top exporters and importers of HS code 283720, 2025
In 2025, the largest exporter of HS code 283720 in UN Comtrade data was China, with 31% of world exports; the largest importer in UN Comtrade data was the United States, with 23% 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 $14M 31% of world exports
- 2 Switzerland $10.0M 22% of world exports
- 3 South Korea $7.7M 17% of world exports
World total: $46M Reported figures on UN Comtrade ↗
Top importers 2025 · share of world imports
- 1 United States $13M 23% of world imports
- 2 China $9.3M 16% of world imports
- 3 Finland $5.8M 10% of world imports
World total: $57M 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 2837.20 8
Brazil splits HS 2837.20 into 8 NCM codes, Mercosur's 8-digit tariff lines.
- 2837.20.1 FerrocyanidesFerrocianetos Group
- 2837.20.11 Sodium ferrocyanideDe sódio
- 2837.20.12 Ferrous ferrocyanideDe ferro II (ferrocianeto ferroso)
- 2837.20.19 Other ferrocyanidesOutros
- 2837.20.2 FerricyanidesFerricianetos Group
- 2837.20.21 Potassium ferricyanideDe potássio
- 2837.20.22 Ferrous ferricyanideDe ferro II (ferricianeto ferroso)
- 2837.20.23 Ferric ferricyanideDe ferro III (ferricianeto férrico)
- 2837.20.29 Other ferricyanidesOutros
- 2837.20.90 Other complex cyanidesOutros
All Brazil NCM codes in heading 28.37 →
Source: Siscomex NCM table, updated Oct 2026. The Portuguese text is official; the English is our translation.
Questions about HS 2837.20
What is HS code 283720?
HS code 283720 is a 6-digit subheading in the Harmonized System that covers: Complex cyanides. This HS code specifically covers complex cyanides, which are distinct from simple cyanides due to their coordination compound structure where the cyanide ion acts as a ligand. Key examples include ferrocyanides (e.g., potassium ferrocyanide, sodium ferrocyanide) and ferricyanides (e.g., potassium ferricyanide). Unlike simple cyanides, these compounds are generally much less toxic and have a broader range of industrial applications. Ferrocyanides are widely used as anti-caking agents in road salt and table salt, as food additives (E535, E536), in the production of pigments like Prussian blue, and in electroplating. Ferricyanides are used in photography, blueprinting, and as mild oxidizing agents in organic synthesis. The trade in complex cyanides involves chemical manufacturers, food ingredient suppliers, and specialized industrial users. Importers are often food processing companies, pigment manufacturers, or photographic chemical suppliers. Exporters are typically chemical producers with advanced synthesis capabilities. While less hazardous than simple cyanides, proper handling and quality control are still important, especially for food-grade applications.
What products fall under HS code 283720?
Potassium ferrocyanide, Sodium ferrocyanide, Potassium ferricyanide, Ammonium ferrocyanide, Prussian blue pigment (as a complex cyanide derivative), Ferric ferrocyanide
What are common misclassifications for HS code 283720?
This code is often confused with simple cyanides (283711, 283719) due to the "cyanide" in the name, but their chemical structure and toxicity profiles are vastly different. It's crucial to distinguish between simple ionic cyanides and these coordination complexes.
Which countries are the top exporters of goods under HS code 283720?
In 2025, the top exporters of HS code 283720 in UN Comtrade data were China ($14M, 31% of world exports), Switzerland ($10.0M) and South Korea ($7.7M). World exports came to about $46M, 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 283720?
In 2025, the top importers of HS code 283720 in UN Comtrade data were the United States ($13M, 23% of world imports), China ($9.3M) and Finland ($5.8M). World imports came to about $57M, 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 283720 structured?
HS code 283720 is a 6-digit subheading under the Harmonized System. The first 2 digits (28) identify the chapter, digits 3-4 (37) identify the heading, and digits 5-6 (20) specify the subheading. This code is standardized globally by the World Customs Organization.
What is the Brazil NCM code for HS code 283720?
Brazil splits HS code 283720 into 8 NCM codes: 2837.20.11 (Sodium ferrocyanide), 2837.20.12 (Ferrous ferrocyanide), 2837.20.19 (Other ferrocyanides), 2837.20.21 (Potassium ferricyanide), 2837.20.22 (Ferrous ferricyanide), 2837.20.23 (Ferric ferricyanide), 2837.20.29 (Other ferricyanides), 2837.20.90 (Other complex cyanides). The first 6 digits of each match the HS code.