Product classification
HS code for HFO-1234ze: 2903.51
Unsaturated fluorinated derivatives of acyclic hydrocarbons, 2,3,3,3-tetrafluoropropene (HFO-1234yf), 1,3,3,3-tetrafluoropropene (HFO-1234ze) and (Z)-1,1,1,4,4,4-hexafluoro-2-butene (HFO-1336mzz).
Classification of HFO-1234ze under HS 2903.51
HFO-1234ze, or 1,3,3,3-tetrafluoropropene, is classified under HS code 2903.51. This classification is distinct from traditional HFCs because HFOs (hydrofluoroolefins) are unsaturated hydrocarbons, meaning they contain at least one carbon-carbon double bond. In the Harmonized System, heading 2903 covers halogenated derivatives of hydrocarbons. While subheadings 2903.41 through 2903.49 are dedicated to saturated derivatives, the 2903.5x and 2903.6x series cover unsaturated derivatives. Specifically, subheading 2903.51 was introduced to group together several key unsaturated fluorinated derivatives, including HFO-1234yf, HFO-1234ze, and HFO-1336mzz. The classification of HFO-1234ze under 2903.51 is mandatory because the chemical is explicitly named in the subheading description. This distinction is vital for regulatory purposes, as unsaturated fluorinated hydrocarbons typically have a significantly lower Global Warming Potential (GWP) than saturated HFCs. Proper classification under 2903.51 ensures that the product is recognized as a next-generation refrigerant or blowing agent, separate from the older, more environmentally impactful substances.
- Covers
- 1,3,3,3-tetrafluoropropene (HFO-1234ze)
- Trans-1,3,3,3-tetrafluoroprop-1-ene
- HFO-1234ze(E) used as a propellant
- HFO-1234ze used as a blowing agent
- Also under 2903.51
- Chemours Opteon YF (HFO-1234yf)
- Honeywell Solstice YF (HFO-1234yf)
- Arkema Forane 1234yf
- Honeywell Solstice ze (HFO-1234ze)
Codes often confused with 2903.51
Common mistake. HFO-1234ze is frequently misclassified under HS code 2903.42 (HFC-32) or 2903.49 due to confusion between saturated HFCs and unsaturated HFOs. Because it is a tetrafluoropropene, it is also sometimes incorrectly placed in 2903.59, which is the category for "other" unsaturated fluorinated derivatives, despite 2903.51 being the specific and correct code.
Top exporters and importers of HS 290351 (the code used for HFO-1234ze), 2025
In 2025, the largest exporter of HS 290351 (the code used for HFO-1234ze) in UN Comtrade data was the United States, with 39% of world exports; the largest importer in UN Comtrade data was the Netherlands, with 29% of world imports. Mexico reports $578M of its heading 2903 imports without product detail (confidential), so it may also belong among the top importers.
Figures cover everything classified under HS 290351, not only HFO-1234ze.
Top exporters 2025 · share of world exports
- 1 United States $611M 39% of world exports
- 2 Netherlands $508M 33% of world exports
- 3 China $295M 19% of world exports
World total: $1.6B Reported figures on UN Comtrade ↗
Top importers 2025 · share of world imports
- 1 Netherlands $412M 29% of world imports
- 2 Germany $123M 8.7% of world imports
- 3 South Korea $122M 8.7% of world imports
Mexico reports $578M of its heading 2903 imports without product detail (confidential), so it may also belong among the top importers.
World total: $1.4B 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 HFO-1234ze
Brazil classifies HFO-1234ze under NCM 2903.51.00: HS 2903.51 with 00 added.
Source: Siscomex NCM table, updated Oct 2026. The Portuguese text on each NCM page is the official one.
Questions about HFO-1234ze
What is the HS code for HFO-1234ze?
The HS code for HFO-1234ze is 290351 (Unsaturated fluorinated derivatives of acyclic hydrocarbons; 2,3,3,3-tetrafluoropropene (HFO-1234yf), 1,3,3,3-tetrafluoropropene (HFO-1234ze) and (Z)-1,1,1,4,4,4-hexafluoro-2-butene (HFO-1336mzz)). The HS code for HFO-1234ze is 2903.51.
How do I classify HFO-1234ze for customs?
HFO-1234ze is classified under HS code 290351 — Unsaturated fluorinated derivatives of acyclic hydrocarbons; 2,3,3,3-tetrafluoropropene (HFO-1234yf), 1,3,3,3-tetrafluoropropene (HFO-1234ze) and (Z)-1,1,1,4,4,4-hexafluoro-2-butene (HFO-1336mzz). This is a 6-digit subheading level code.
How does HFO-1234ze differ from HFCs in classification?
HFO-1234ze is an unsaturated derivative (containing a double bond), which places it in the 2903.5x series, whereas saturated HFCs are placed in the 2903.4x series.
Which countries are the top exporters of HFO-1234ze (HS 290351)?
In 2025, the top exporters of HS 290351 (the code used for HFO-1234ze) in UN Comtrade data were the United States ($611M, 39% of world exports), the Netherlands ($508M) and China ($295M). World exports came to about $1.6B, 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 HFO-1234ze (HS 290351)?
In 2025, the top importers of HS 290351 (the code used for HFO-1234ze) in UN Comtrade data were the Netherlands ($412M, 29% of world imports), Germany ($123M) and South Korea ($122M). World imports came to about $1.4B, adding countries' reported figures and partner-based estimates for those that did not report (UN Comtrade data). Mexico reports $578M of its heading 2903 imports without product detail (confidential), so it may also belong among the top importers.
Is the HS code for HFO-1234ze the same in all countries?
The base HS code 290351 for HFO-1234ze 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 HFO-1234ze in Brazil?
In Brazil, HFO-1234ze (HS 290351) is classified under NCM 2903.51.00.