Product classification
HS code for HFO-1234yf: 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-1234yf under HS 2903.51
HFO-1234yf (2,3,3,3-tetrafluoropropene) is classified under HS code 2903.51. This classification is distinct from HFCs because HFOs (hydrofluoroolefins) are unsaturated fluorinated derivatives of acyclic hydrocarbons. The term \"unsaturated\" refers to the presence of at least one double bond in the carbon chain, which distinguishes HFOs from saturated HFCs found in the 2903.4x series. Heading 2903 covers halogenated derivatives, and the 2022 HS nomenclature introduced subheading 2903.51 to specifically account for HFO-1234yf, HFO-1234ze, and HFO-1336mzz. These chemicals are increasingly used as low-GWP (Global Warming Potential) refrigerants. Classification under 2903.51 is mandatory for the pure substance, as it is specifically named in the Harmonized System legal notes. This ensures that customs authorities can distinguish these newer, more environmentally friendly gases from older fluorinated gases.
- Covers
- 2,3,3,3-tetrafluoropropene (HFO-1234yf)
- 1,3,3,3-tetrafluoropropene (HFO-1234ze)
- (Z)-1,1,1,4,4,4-hexafluoro-2-butene (HFO-1336mzz)
- Pure HFO-1234yf used in mobile air conditioning (MAC) systems
- 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-1234yf is frequently misclassified under 2903.45 (tetrafluoroethanes) or 2903.49 (other saturated HFCs). This is a technical error because HFO-1234yf is a propene (three carbons with a double bond), not an ethane (two carbons, saturated). Another common error is classification under 3824.78. While many new refrigerants are mixtures (which belong in 3824), pure HFO-1234yf must be classified in Chapter 29.
Top exporters and importers of HS 290351 (the code used for HFO-1234yf), 2025
In 2025, the largest exporter of HS 290351 (the code used for HFO-1234yf) 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-1234yf.
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-1234yf
Brazil classifies HFO-1234yf 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-1234yf
What is the HS code for HFO-1234yf?
The HS code for HFO-1234yf 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 pure HFO-1234yf is 2903.51.
How do I classify HFO-1234yf for customs?
HFO-1234yf 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.
Why is HFO-1234yf not classified with HFC-134a?
HFC-134a is a saturated hydrocarbon (2903.45), whereas HFO-1234yf is an unsaturated hydrocarbon (2903.51). The double bond in HFO-1234yf changes its chemical classification and its HS code.
Which countries are the top exporters of HFO-1234yf (HS 290351)?
In 2025, the top exporters of HS 290351 (the code used for HFO-1234yf) 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-1234yf (HS 290351)?
In 2025, the top importers of HS 290351 (the code used for HFO-1234yf) 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-1234yf the same in all countries?
The base HS code 290351 for HFO-1234yf 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-1234yf in Brazil?
In Brazil, HFO-1234yf (HS 290351) is classified under NCM 2903.51.00.