Product classification
HS code for Perfluorooctane sulfonic acid: 2904.31
Derivatives of hydrocarbons, perfluorooctane sulphonic acid, whether or not halogenated.
Classification of perfluorooctane sulfonic acid under HS 2904.31
Perfluorooctane sulfonic acid (PFOS) is classified under HS code 2904.31. This substance is an organic chemical belonging to the sulfonated derivatives of hydrocarbons. Chapter 29 covers organic chemicals, and heading 2904 specifically addresses derivatives containing sulfonated, nitrated, or nitrosated groups. The subheading 2904.31 was created to facilitate the monitoring of PFOS, which is a persistent organic pollutant (POP) regulated under the Stockholm Convention. Classification is based on the chemical structure: a fully fluorinated eight-carbon chain attached to a sulfonic acid group. This code applies to the acid form of the chemical. Because of its high level of regulation, customs authorities require precise documentation to distinguish the pure acid from its salts or other derivatives. The classification follows GRI 1, as the subheading explicitly names perfluorooctane sulfonic acid.
- Covers
- Perfluorooctane sulfonic acid (PFOS)
- Heptadecafluorooctane-1-sulfonic acid
- Perfluorooctane sulfonate (acid form)
- Pure PFOS chemical samples
- Fluorinated hydrocarbon sulfonated derivatives
- Also under 2904.31
- 3M (historical producer of PFOS, now phased out)
- Chemours (fluorochemicals, but PFOS largely restricted)
- Daikin (fluorochemicals, but PFOS largely restricted)
Codes often confused with 2904.31
Common mistake. PFOS is often confused with its salts, such as ammonium perfluorooctane sulfonate, which is classified under HS code 2904.32. Other salts like lithium, potassium, or zinc salts of PFOS fall under codes 2904.33 through 2904.36. Another common misclassification is HS code 3824.99, used for industrial chemical mixtures. If PFOS is part of a fire-fighting foam or a textile treatment solution, it is no longer a separate chemically defined compound and must be classified in Chapter 38. Finally, it should not be confused with PFOA (Perfluorooctanoic acid), which is a carboxylic acid classified in heading 2915.
Top exporters and importers of HS 290431 (the code used for perfluorooctane sulfonic acid), 2025
In 2025, the largest exporter of HS 290431 (the code used for perfluorooctane sulfonic acid) in UN Comtrade data was Portugal, with 71% of world exports; the largest importer in UN Comtrade data was Nigeria, with 52% 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 290431, not only perfluorooctane sulfonic acid.
Top exporters 2025 · share of world exports
- 1 Portugal $631K 71% of world exports
- 2 Egypt $66K 7.4% of world exports
- 3 Germany $56K 6.3% of world exports
World total: $894K Reported figures on UN Comtrade ↗
Top importers 2025 · share of world imports
- 1 Nigeria $485K 52% of world imports
- 2 Cape Verde* ~$105K 11% of world imports · partner records ↗
- 3 Algeria* ~$66K 7.1% of world imports · partner records ↗
World total: $931K 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 marked * did not, so their figures add up what other countries recorded trading with them, and their exports are valued at buyers' CIF prices. 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 perfluorooctane sulfonic acid
Brazil classifies perfluorooctane sulfonic acid under NCM 2904.31.00: HS 2904.31 with 00 added.
Source: Siscomex NCM table, updated Oct 2026. The Portuguese text on each NCM page is the official one.
Questions about perfluorooctane sulfonic acid
What is the HS code for Perfluorooctane sulfonic acid?
The HS code for Perfluorooctane sulfonic acid is 290431 (Derivatives of hydrocarbons; perfluorooctane sulphonic acid, whether or not halogenated).
How do I classify Perfluorooctane sulfonic acid for customs?
Perfluorooctane sulfonic acid is classified under HS code 290431 — Derivatives of hydrocarbons; perfluorooctane sulphonic acid, whether or not halogenated. This is a 6-digit subheading level code.
What is the HS code for PFOS?
The HS code for the acid form of perfluorooctane sulfonic acid is 2904.31.
Are PFOS salts classified under the same code?
No, salts of PFOS are classified in separate subheadings ranging from 2904.32 to 2904.36, depending on the specific cation (e.g., ammonium, lithium).
Which countries are the top exporters of perfluorooctane sulfonic acid (HS 290431)?
In 2025, the top exporters of HS 290431 (the code used for perfluorooctane sulfonic acid) in UN Comtrade data were Portugal ($631K, 71% of world exports), Egypt ($66K) and Germany ($56K). World exports came to about $894K, 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 perfluorooctane sulfonic acid (HS 290431)?
In 2025, the top importers of HS 290431 (the code used for perfluorooctane sulfonic acid) in UN Comtrade data were Nigeria ($485K, 52% of world imports), Cape Verde (about $105K) and Algeria (about $66K). World imports came to about $931K, 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 Perfluorooctane sulfonic acid the same in all countries?
The base HS code 290431 for Perfluorooctane sulfonic acid 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 perfluorooctane sulfonic acid in Brazil?
In Brazil, perfluorooctane sulfonic acid (HS 290431) is classified under NCM 2904.31.00.