Product classification
HS code for Butene: 2901.23
Acyclic hydrocarbons, unsaturated, butene (butylene) and isomers thereof.
Classification of butene under HS 2901.23
The classification of Butene under HS code 2901.23 is determined by its chemical structure as an acyclic unsaturated hydrocarbon. According to the General Rules of Interpretation (GRI), specifically Rule 1, products are classified based on the terms of the headings and any relative section or chapter notes. Heading 2901 covers acyclic hydrocarbons, and the subheading 2901.23 is specifically reserved for butene (butylene) and its various isomers. These compounds consist of four carbon atoms and eight hydrogen atoms with one double bond. To be classified here, the substance must be a separate chemically defined compound, typically meeting high purity standards. This classification applies regardless of whether the butene is 1-butene, 2-butene, or isobutylene, as the HS nomenclature groups these isomers together under a single code to simplify international trade and monitoring of petrochemical feedstocks.
- Covers
- 1-Butene (alpha-butylene)
- (Z)-But-2-ene (cis-2-butylene)
- (E)-But-2-ene (trans-2-butylene)
- Isobutylene (2-methylpropene)
- Mixed isomers of butene of high purity
- Also under 2901.23
- ExxonMobil Chemical (producer of isobutylene)
- LyondellBasell (producer of 1-butene)
- SABIC (producer)
- INEOS (producer)
- BASF (producer)
Codes often confused with 2901.23
Common mistake. Butene is frequently misclassified under HS code 2711.14 (Liquefied ethylene) or 2711.19 (Other liquefied petroleum gases). The primary distinction lies in the purity and the intended use. Chapter 27 is generally for mineral fuels and oils, whereas Chapter 29 is for separate chemically defined organic compounds. If the butene is part of a crude mixture of hydrocarbons intended for use as fuel, it belongs in Chapter 27. Another common error is confusing it with 2901.24, which covers buta-1,3-diene and isoprene; these are dienes (two double bonds) rather than mono-alkenes like butene.
Top exporters and importers of HS 290123 (the code used for butene), 2025
In 2025, the largest exporter of HS 290123 (the code used for butene) in UN Comtrade data was the United States, with 31% of world exports; the largest importer in UN Comtrade data was Canada, with 34% 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 290123, not only butene.
Top exporters 2025 · share of world exports
- 1 United States $198M 31% of world exports
- 2 Belgium $183M 29% of world exports
- 3 South Korea $71M 11% of world exports
World total: $640M Reported figures on UN Comtrade ↗
Top importers 2025 · share of world imports
- 1 Canada $192M 34% of world imports
- 2 Germany $52M 9.3% of world imports
- 3 Thailand $43M 7.7% of world imports
World total: $558M 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 butene
Brazil classifies butene under NCM 2901.23.00: HS 2901.23 with 00 added.
Source: Siscomex NCM table, updated Oct 2026. The Portuguese text on each NCM page is the official one.
Questions about butene
What is the HS code for Butene?
The HS code for Butene is 290123 (Acyclic hydrocarbons; unsaturated, butene (butylene) and isomers thereof). The HS code for Butene and its isomers is 2901.23, which falls under the category of acyclic unsaturated hydrocarbons.
How do I classify Butene for customs?
Butene is classified under HS code 290123 — Acyclic hydrocarbons; unsaturated, butene (butylene) and isomers thereof. This is a 6-digit subheading level code.
Are butene isomers classified under different codes?
No, all isomers of butene, including 1-butene and isobutylene, are grouped together under the same HS code 2901.23.
Which countries are the top exporters of butene (HS 290123)?
In 2025, the top exporters of HS 290123 (the code used for butene) in UN Comtrade data were the United States ($198M, 31% of world exports), Belgium ($183M) and South Korea ($71M). World exports came to about $640M, 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 butene (HS 290123)?
In 2025, the top importers of HS 290123 (the code used for butene) in UN Comtrade data were Canada ($192M, 34% of world imports), Germany ($52M) and Thailand ($43M). World imports came to about $558M, 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 Butene the same in all countries?
The base HS code 290123 for Butene 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 butene in Brazil?
In Brazil, butene (HS 290123) is classified under NCM 2901.23.00.