Product classification
HS code for PFOS salts: 2904.35
Derivatives of hydrocarbons, salts of perfluorooctane sulphonic acid n.e.c in heading no. 2904, whether or not halogenated.
Classification of PFOS salts under HS 2904.35
PFOS salts are classified under HS code 2904.35. As derivatives of hydrocarbons, these substances fall under Chapter 29 (Organic Chemicals) and heading 2904. While the parent acid is found in 2904.31, the salts—formed when the sulfonic acid group reacts with a base—are specifically isolated in 2904.35. This distinction is vital for international trade monitoring under environmental treaties. To be classified here, the salt must be a separate chemically defined compound. Common cations include potassium, lithium, and ammonium. These salts are often used in industrial applications for their surfactant properties, but their classification remains in Chapter 29 as long as they are not mixed with other substances for a specific functional use.
- Covers
- Potassium perfluorooctane sulfonate
- Lithium perfluorooctane sulfonate
- Ammonium perfluorooctane sulfonate
- Diethanolammonium perfluorooctane sulfonate
- Tetraethylammonium perfluorooctane sulfonate
- Didecyldimethylammonium perfluorooctane sulfonate
- Also under 2904.35
- 3M (historical producer)
- Chemours (fluorochemicals, but PFOS salts largely restricted)
- Daikin (fluorochemicals, but PFOS salts largely restricted)
Codes often confused with 2904.35
Common mistake. The most common misclassification is using HS code 2904.31, which is strictly for the acid form (PFOS). Another frequent error is using 3824.87, which is for mixtures. If the salt is imported as a pure chemical, it belongs in 2904.35; if it is imported as part of a formulated product (like a carpet cleaner or stain repellant), it must be classified in Chapter 38 or the specific heading for that preparation.
Top exporters and importers of HS 290435 (the code used for PFOS salts), 2025
In 2025, the largest exporter of HS 290435 (the code used for PFOS salts) in UN Comtrade data was the United States, with 78% of world exports; the largest importer in UN Comtrade data was Canada, with 83% 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 290435, not only PFOS salts.
Top exporters 2025 · share of world exports
- 1 United States $766K 78% of world exports
- 2 South Africa $129K 13% of world exports
- 3 France $73K 7.4% of world exports
World total: $985K Reported figures on UN Comtrade ↗
Top importers 2025 · share of world imports
- 1 Canada $1.0M 83% of world imports
- 2 Zambia* ~$101K 8.3% of world imports · partner records ↗
- 3 Malawi $49K 4.0% of world imports
World total: $1.2M 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 PFOS salts
Brazil classifies PFOS salts under NCM 2904.35.00: HS 2904.35 with 00 added.
Source: Siscomex NCM table, updated Oct 2026. The Portuguese text on each NCM page is the official one.
Questions about PFOS salts
What is the HS code for PFOS salts?
The HS code for PFOS salts is 290435 (Derivatives of hydrocarbons; salts of perfluorooctane sulphonic acid n.e.c in heading no. 2904, whether or not halogenated). The HS code for salts of perfluorooctane sulphonic acid is 2904.35.
How do I classify PFOS salts for customs?
PFOS salts is classified under HS code 290435 — Derivatives of hydrocarbons; salts of perfluorooctane sulphonic acid n.e.c in heading no. 2904, whether or not halogenated. This is a 6-digit subheading level code.
Is potassium PFOS classified under this code?
Yes, potassium perfluorooctane sulfonate is one of the primary salts classified under HS code 2904.35.
Which countries are the top exporters of PFOS salts (HS 290435)?
In 2025, the top exporters of HS 290435 (the code used for PFOS salts) in UN Comtrade data were the United States ($766K, 78% of world exports), South Africa ($129K) and France ($73K). World exports came to about $985K, 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 PFOS salts (HS 290435)?
In 2025, the top importers of HS 290435 (the code used for PFOS salts) in UN Comtrade data were Canada ($1.0M, 83% of world imports), Zambia (about $101K) and Malawi ($49K). World imports came to about $1.2M, 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 PFOS salts the same in all countries?
The base HS code 290435 for PFOS salts 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 PFOS salts in Brazil?
In Brazil, PFOS salts (HS 290435) is classified under NCM 2904.35.00.