HS code · 6-digit subheading
HS Code 2931.20 – Organo-inorganic compounds; tributyltin compounds
HS code 2931.20 is the 6-digit subheading for organo-inorganic compounds, tributyltin compounds. It is used for tributyltin oxide (TBTO), tributyltin chloride (TBTC), tributyltin methacrylate, TBT compounds and organotin biocides.
What HS 2931.20 covers
This HS code covers tributyltin (TBT) compounds, a group of organo-inorganic chemicals historically used as potent biocides, particularly in antifouling paints for ships and as wood preservatives. However, TBT compounds are highly toxic to marine life, causing severe environmental damage, and have been largely banned or severely restricted globally by international conventions like the IMO's AFS Convention. International trade in these substances is now extremely limited, primarily for very specific industrial applications where no suitable alternatives exist, or for research purposes, and is subject to strict regulatory oversight. Importers are typically specialized chemical industries or research institutions in countries that still permit their use under specific, tightly controlled exemptions. Exporters are usually a small number of specialized chemical manufacturers capable of producing these compounds under strict environmental and safety protocols. Key things to know include their severe environmental impact, the global phase-out for most applications, and the stringent controls on any remaining trade. Any trade activity must comply with international environmental treaties and national chemical regulations, making this a highly sensitive category.
- Covers
- Tributyltin oxide (TBTO)
- Tributyltin chloride (TBTC)
- Tributyltin methacrylate
- TBT compounds
- Organotin biocides
- Antifouling paint additive
- Examples
- Sigma-Aldrich TBTO
- Merck TBTC
- Arkema TBT compounds (historical)
- Dow Chemical TBT (historical)
Codes often confused with 2931.20
Common mistake. TBT compounds might be confused with other organotin compounds in 2931.90 or other biocides in Chapter 38, but their specific chemical structure and high toxicity warrant this distinct classification.
Top exporters and importers of HS code 293120, 2025
In 2025, the largest exporter of HS code 293120 in UN Comtrade data was the United States, with 35% of world exports; the largest importer in UN Comtrade data was Belgium, with 33% 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 United States $1.6M 35% of world exports
- 2 Germany $804K 18% of world exports
- 3 Netherlands $653K 15% of world exports
World total: $4.5M Reported figures on UN Comtrade ↗
Top importers 2025 · share of world imports
- 1 Belgium $3.4M 33% of world imports
- 2 Italy $1.1M 11% of world imports
- 3 India $1.1M 10% of world imports
World total: $10M 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 code for 2931.20
Brazil does not split HS 2931.20: its NCM code is 2931.20.00.
All Brazil NCM codes in heading 29.31 →
Source: Siscomex NCM table, updated Oct 2026. The Portuguese text is official; the English is our translation.
Questions about HS 2931.20
What is HS code 293120?
HS code 293120 is a 6-digit subheading in the Harmonized System that covers: Organo-inorganic compounds; tributyltin compounds. This HS code covers tributyltin (TBT) compounds, a group of organo-inorganic chemicals historically used as potent biocides, particularly in antifouling paints for ships and as wood preservatives. However, TBT compounds are highly toxic to marine life, causing severe environmental damage, and have been largely banned or severely restricted globally by international conventions like the IMO's AFS Convention. International trade in these substances is now extremely limited, primarily for very specific industrial applications where no suitable alternatives exist, or for research purposes, and is subject to strict regulatory oversight. Importers are typically specialized chemical industries or research institutions in countries that still permit their use under specific, tightly controlled exemptions. Exporters are usually a small number of specialized chemical manufacturers capable of producing these compounds under strict environmental and safety protocols. Key things to know include their severe environmental impact, the global phase-out for most applications, and the stringent controls on any remaining trade. Any trade activity must comply with international environmental treaties and national chemical regulations, making this a highly sensitive category.
What products fall under HS code 293120?
Tributyltin oxide (TBTO), Tributyltin chloride (TBTC), Tributyltin methacrylate, TBT compounds, Organotin biocides, Antifouling paint additive
What are common misclassifications for HS code 293120?
TBT compounds might be confused with other organotin compounds in 2931.90 or other biocides in Chapter 38, but their specific chemical structure and high toxicity warrant this distinct classification.
Which countries are the top exporters of goods under HS code 293120?
In 2025, the top exporters of HS code 293120 in UN Comtrade data were the United States ($1.6M, 35% of world exports), Germany ($804K) and the Netherlands ($653K). World exports came to about $4.5M, 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 293120?
In 2025, the top importers of HS code 293120 in UN Comtrade data were Belgium ($3.4M, 33% of world imports), Italy ($1.1M) and India ($1.1M). World imports came to about $10M, 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 293120 structured?
HS code 293120 is a 6-digit subheading under the Harmonized System. The first 2 digits (29) identify the chapter, digits 3-4 (31) 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 293120?
In Brazil, HS code 293120 is NCM 2931.20.00. The last two digits are 00 because Brazil does not split this HS code further.