Product classification
HS code for Butylene: 2901.23
Acyclic hydrocarbons, unsaturated, butene (butylene) and isomers thereof.
Classification of butylene under HS 2901.23
Butylene, also systematically known as butene, represents a group of unsaturated acyclic hydrocarbons. Its classification under HS code 2901.23 is highly precise, as this subheading specifically covers "butene (butylene) and isomers thereof" within the broader category of "Unsaturated acyclic hydrocarbons" (2901.2X). This designation accurately encompasses all structural isomers of butene, including 1-butene, cis-2-butene, trans-2-butene, and isobutylene (2-methylpropene). These compounds are characterized by a four-carbon chain containing one double bond, making them crucial intermediates in the petrochemical industry. Their inclusion in Chapter 29, which is dedicated to organic chemicals, reflects their fundamental role as chemical building blocks and their defined molecular structure.
- Covers
- 1-Butene
- Cis-2-Butene
- Trans-2-Butene
- Isobutylene (2-methylpropene)
- Butene mixtures containing these isomers
- 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. Accurate classification of butylene requires careful attention to its chemical structure. HS 2901.10, which covers "Saturated acyclic hydrocarbons" like butane, is a potential source of misclassification if the unsaturated nature (presence of a double bond) of butylene is overlooked. The distinction between saturated and unsaturated hydrocarbons is fundamental within Chapter 29. Furthermore, other unsaturated acyclic hydrocarbons, such as ethylene (HS 2901.21) and propene (propylene) (HS 2901.22), might be confused with butylene. However, these codes are specifically for two-carbon and three-carbon alkenes, respectively. The explicit mention of "butene (butylene) and isomers thereof" in 2901.23 clearly differentiates it based on its four-carbon chain length, ensuring precise classification.
Top exporters and importers of HS 290123 (the code used for butylene), 2025
In 2025, the largest exporter of HS 290123 (the code used for butylene) 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 butylene.
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 butylene
Brazil classifies butylene 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 butylene
What is the HS code for Butylene?
The HS code for Butylene is 290123 (Acyclic hydrocarbons; unsaturated, butene (butylene) and isomers thereof). The HS code for Butylene is 2901.23.
How do I classify Butylene for customs?
Butylene is classified under HS code 290123 — Acyclic hydrocarbons; unsaturated, butene (butylene) and isomers thereof. This is a 6-digit subheading level code.
What are the main industrial applications of Butylene?
Butylene is primarily used as a monomer in the production of various polymers, including polybutene and butyl rubber, and as an intermediate in the synthesis of other organic chemicals and fuels.
Which countries are the top exporters of butylene (HS 290123)?
In 2025, the top exporters of HS 290123 (the code used for butylene) 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 butylene (HS 290123)?
In 2025, the top importers of HS 290123 (the code used for butylene) 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 Butylene the same in all countries?
The base HS code 290123 for Butylene 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 butylene in Brazil?
In Brazil, butylene (HS 290123) is classified under NCM 2901.23.00.