HS code · 6-digit subheading
HS Code 2904.31 – Derivatives of hydrocarbons; perfluorooctane sulphonic acid, whether or not halogenated
HS code 2904.31 is the 6-digit subheading for derivatives of hydrocarbons, perfluorooctane sulphonic acid, whether or not halogenated. It is used for perfluorooctane sulfonic acid (PFOS), potassium perfluorooctane sulfonate, ammonium perfluorooctane sulfonate, lithium perfluorooctane sulfonate and PFOS-based fire fighting foam concentrates.
What HS 2904.31 covers
This specific HS code targets Perfluorooctane Sulphonic Acid (PFOS), a synthetic fluorinated compound known for its surfactant properties and chemical stability. PFOS and its derivatives have been widely used in various industrial and consumer products due to their water and oil repellent characteristics. Historically, it was a key ingredient in fire-fighting foams, metal plating, textiles, paper coatings, and photographic materials. However, due to its persistence in the environment, bioaccumulation, and potential toxicity, PFOS is now largely restricted or banned under international agreements like the Stockholm Convention. Trade in PFOS is highly regulated, with most countries phasing out its production and use. Importers might include specialized industries with specific exemptions for critical applications, or those involved in remediation efforts. Exporters are typically chemical companies in countries that previously manufactured PFOS, now managing existing stocks or producing for very limited, approved uses. Key things to know are the stringent international regulations, the need for proper documentation for any permitted trade, and the ongoing global efforts to find safer alternatives.
- Covers
- Perfluorooctane sulfonic acid (PFOS)
- Potassium perfluorooctane sulfonate
- Ammonium perfluorooctane sulfonate
- Lithium perfluorooctane sulfonate
- PFOS-based fire fighting foam concentrates
- PFOS-containing textile treatments
- Examples
- 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. Can be confused with other per- and polyfluoroalkyl substances (PFAS) under different HS codes, such as PFOA (Perfluorooctanoic acid) or its salts, which fall under other specific subheadings or broader organic fluorine compounds (e.g., 2903).
Top exporters and importers of HS code 290431, 2025
In 2025, the largest exporter of HS code 290431 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.
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 2904.31
Brazil does not split HS 2904.31: its NCM code is 2904.31.00.
All Brazil NCM codes in heading 29.04 →
Source: Siscomex NCM table, updated Oct 2026. The Portuguese text is official; the English is our translation.
Questions about HS 2904.31
What is HS code 290431?
HS code 290431 is a 6-digit subheading in the Harmonized System that covers: Derivatives of hydrocarbons; perfluorooctane sulphonic acid, whether or not halogenated. This specific HS code targets Perfluorooctane Sulphonic Acid (PFOS), a synthetic fluorinated compound known for its surfactant properties and chemical stability. PFOS and its derivatives have been widely used in various industrial and consumer products due to their water and oil repellent characteristics. Historically, it was a key ingredient in fire-fighting foams, metal plating, textiles, paper coatings, and photographic materials. However, due to its persistence in the environment, bioaccumulation, and potential toxicity, PFOS is now largely restricted or banned under international agreements like the Stockholm Convention. Trade in PFOS is highly regulated, with most countries phasing out its production and use. Importers might include specialized industries with specific exemptions for critical applications, or those involved in remediation efforts. Exporters are typically chemical companies in countries that previously manufactured PFOS, now managing existing stocks or producing for very limited, approved uses. Key things to know are the stringent international regulations, the need for proper documentation for any permitted trade, and the ongoing global efforts to find safer alternatives.
What products fall under HS code 290431?
Perfluorooctane sulfonic acid (PFOS), Potassium perfluorooctane sulfonate, Ammonium perfluorooctane sulfonate, Lithium perfluorooctane sulfonate, PFOS-based fire fighting foam concentrates, PFOS-containing textile treatments
What are common misclassifications for HS code 290431?
Can be confused with other per- and polyfluoroalkyl substances (PFAS) under different HS codes, such as PFOA (Perfluorooctanoic acid) or its salts, which fall under other specific subheadings or broader organic fluorine compounds (e.g., 2903).
Which countries are the top exporters of goods under HS code 290431?
In 2025, the top exporters of HS code 290431 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 goods under HS code 290431?
In 2025, the top importers of HS code 290431 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.
How is HS code 290431 structured?
HS code 290431 is a 6-digit subheading under the Harmonized System. The first 2 digits (29) identify the chapter, digits 3-4 (04) identify the heading, and digits 5-6 (31) specify the subheading. This code is standardized globally by the World Customs Organization.
What is the Brazil NCM code for HS code 290431?
In Brazil, HS code 290431 is NCM 2904.31.00. The last two digits are 00 because Brazil does not split this HS code further.