HS 290432 Ammonium perfluorooctane sulphonate
Quick Answer: HS code 290432 specifically covers Ammonium Perfluorooctane Sulphonate (APFOS), a synthetic organic chemical compound. This substance is primarily used as a surfactant in various industrial applications, including fire-fighting foams, metal plating, and as a processing aid in the production of fluoropolymers. Importers and exporters should note the varying duty rates: the UK applies a 0.00% ad valorem duty, while the EU imposes a 5.50% ad valorem rate. For the US, the general duty rate is 3.7% ad valorem, with many countries benefiting from duty-free treatment under various trade agreements (e.g., Australia, Korea, Singapore). However, a 25% ad valorem rate may apply under specific trade measures. Due to its per- and polyfluoroalkyl substances (PFAS) classification, APFOS is subject to increasing regulatory scrutiny globally, impacting its trade and use.
What Are the Import Duty Rates?
🇬🇧 United Kingdom
| Code | MFN | Preferential | Unit |
|---|---|---|---|
| 2904320000 | 0.00 % | — | — |
🇪🇺 European Union (TARIC)
| Code | MFN | Preferential | Unit |
|---|---|---|---|
| 2904320000 | 5.50 % | — | — |
🇺🇸 United States (HTSUS)
| Code | MFN | Preferential | Unit |
|---|---|---|---|
| 2904320000 | 3.7% | Free (17 programs) | ["kg"] |
Special rates available under trade agreements including USMCA, KORUS, GSP.
Duty rates sourced from the USITC (US International Trade Commission) Harmonized Tariff Schedule (HTS) (accessed 2/22/2026), EU TARIC – DG TAXUD (Directorate-General for Taxation and Customs Union) (accessed 2/22/2026), and UK Trade Tariff – HMRC (His Majesty's Revenue and Customs) (accessed 2/22/2026).
Data compiled and presented by HSRates.
Which Trade Agreements Reduce Duties for HS 2904.32?
Imports of Ammonium perfluorooctane sulphonate may qualify for reduced or zero duty rates under free trade agreements and preferential programs. The overview below shows available preferential arrangements by jurisdiction, compiled by HSRates from official tariff and trade agreement data.
United States (HTSUS)
Free for USMCA, KORUS, GSP, and 14 other programs
European Union (TARIC)
Preferential rate data not yet available.
United Kingdom
Preferential rate data not yet available.
Preferential rates require proof of origin and may be subject to quotas or conditions. Always verify eligibility with a licensed customs broker.
Data compiled by HSRates.
Which Preferential Rates Apply to Your Origin Country?
Select an origin country to see if preferential rates apply.
Preferential rates based on available trade agreements. Actual rates may vary.
How Has Trade Volume Developed?
How to Classify This HS Code?
What products does HS 290432 cover?
This subheading covers ammonium perfluorooctane sulphonate (APFOS), a specific chemical compound classified under Heading 2904 of the Harmonized System. Heading 2904 encompasses halogenated, sulphonated, nitrated, or nitrosated derivatives of hydrocarbons, whether or not acyclic. APFOS is a perfluorinated compound, specifically an ammonium salt of perfluorooctane sulfonic acid (PFOS), which is a fully fluorinated organic compound. Its precise chemical structure and functional groups, including the ammonium cation and the perfluorooctane sulphonate anion, define its placement here, as detailed in the World Customs Organization (WCO) Harmonized System Nomenclature and reflected in national tariffs like the USITC Harmonized Tariff Schedule (HTSUS) and the EU TARIC system.
What falls outside HS 290432?
The following products are excluded from HS 290432: perfluorooctane sulfonic acid (PFOS) itself, which would typically fall under a different subheading within 2904 if not in salt form, or other salts of PFOS (e.g., potassium perfluorooctane sulphonate), which would be classified under 2904.39. Additionally, mixtures containing APFOS where other components impart the essential character, or preparations containing APFOS that are specifically provided for elsewhere (e.g., fire-fighting foams, surface-active preparations), would be excluded. For instance, a fire-extinguishing preparation containing APFOS would be classified under Chapter 38, not Chapter 29, due to its functional use and the essential character imparted by the preparation.
What are common classification mistakes for HS 290432?
A common error is misclassifying other perfluorooctane sulphonate salts, such as potassium or sodium salts, under 290432, which is specifically reserved for the ammonium salt. These other salts properly belong in subheading 290439 ("Other"). Another mistake involves classifying mixtures or preparations containing ammonium perfluorooctane sulphonate here, rather than under a more specific heading in Chapter 38 or elsewhere, based on General Interpretative Rule (GRI) 3(b) which addresses mixtures and composite goods. Importers must carefully distinguish between the pure chemical compound and its derivatives or formulated products, ensuring the specific cation is ammonium for 290432.
How should importers classify products under HS 290432?
The correct procedure for classifying products under HS 290432 involves verifying the precise chemical identity of the substance. Importers and customs brokers must ensure that the product is indeed ammonium perfluorooctane sulphonate and not another salt or a mixture. This requires reviewing the Certificate of Analysis (CoA), Safety Data Sheet (SDS), and chemical structure. Application of General Interpretative Rule 1 dictates that classification is determined according to the terms of the headings and any relative section or chapter notes. If the product is the pure ammonium salt, 290432 is appropriate. If it's a mixture or preparation, GRIs 3(b) or 3(c) may lead to classification elsewhere, often in Chapter 38, based on essential character or last-in-numerical-order rule.
Which HS Codes Are Related?
Not the right code? Search all HS codes to find the correct tariff classification.
FAQ
What is the Most Favored Nation (MFN) duty rate for HS 290432 (Ammonium perfluorooctane sulphonate) in the United States, and are there any preferential rates available?
For imports into the United States, the Most Favored Nation (MFN) duty rate for Harmonized System (HS) code 2904.32.00.00 (Ammonium perfluorooctane sulphonate) is 3.7% ad valorem under the Harmonized Tariff Schedule of the United States (HTSUS) General column 1. Preferential duty rates are available under various Free Trade Agreements (FTAs) and trade preference programs. For example, imports from countries designated as A, AU, BH, CL, CO, D, E, IL, JO, KR, MA, OM, P, PA, PE, S, SG may be Free of duty, provided all origin requirements are met. Importers should consult the latest HTSUS and specific FTA rules of origin to confirm eligibility and documentation requirements for preferential treatment. (Source: USITC HTSUS).
How is Ammonium perfluorooctane sulphonate (HS 290432) classified, and what are the key criteria for this specific HS subheading?
Ammonium perfluorooctane sulphonate is classified under HS subheading 2904.32, which specifically covers 'Perfluorooctane sulphonic acid, its salts and perfluorooctane sulphonyl fluoride'. This classification falls within Chapter 29 of the Harmonized System, dedicated to 'Organic chemicals'. The key criteria for classification under this subheading are the chemical structure, specifically the presence of the perfluorooctane sulphonate moiety and its form as an ammonium salt. It is crucial that the product is a chemically defined organic compound, as mixtures or preparations containing this substance would likely be classified elsewhere, typically in Chapter 38, if they are not chemically defined pure substances. Importers should ensure their product's chemical name and structure precisely match the description to avoid misclassification. (Source: WCO Explanatory Notes to Chapter 29).
What documentation is typically required for importing Ammonium perfluorooctane sulphonate (HS 290432), especially when claiming preferential duty rates?
When importing Ammonium perfluorooctane sulphonate (HS 290432), standard import documentation includes a commercial invoice, packing list, bill of lading or air waybill, and a customs declaration. For claiming preferential duty rates under a Free Trade Agreement (FTA), specific origin documentation is mandatory. This typically involves a Certificate of Origin (e.g., USMCA Certificate of Origin, Korea-US FTA Certificate of Origin) or an origin declaration, completed by the exporter, attesting that the goods meet the relevant rules of origin. Importers must retain these documents for a specified period (e.g., 5 years in the US) and be prepared to present them to customs authorities upon request. Failure to provide valid origin documentation will result in the application of the MFN duty rate. Additionally, a Safety Data Sheet (SDS) is often required for chemical products for hazard communication purposes. (Source: Customs regulations of importing countries, e.g., 19 CFR for US Customs).
Are there any specific trade agreements that offer duty-free access for HS 290432, and what are the general requirements to benefit from them?
Yes, numerous trade agreements offer duty-free access for HS 290432. For instance, countries participating in agreements with the US such as the Australia Free Trade Agreement (AUFTA), Bahrain Free Trade Agreement (BHFTA), Chile Free Trade Agreement (CLFTA), Colombia Trade Promotion Agreement (COTPA), Korea-US Free Trade Agreement (KORUS FTA), Panama Trade Promotion Agreement (PATPA), Peru Trade Promotion Agreement (PETPA), and Singapore Free Trade Agreement (SGFTA) may qualify for a Free duty rate. To benefit from these agreements, the Ammonium perfluorooctane sulphonate must meet the specific 'rules of origin' outlined in each respective agreement. These rules typically involve criteria such as the product being wholly obtained or produced in the partner country, or undergoing substantial transformation (e.g., a change in tariff classification or a regional value content requirement) within the partner country. Importers must obtain a valid Certificate of Origin or equivalent declaration from the exporter and ensure compliance with all procedural requirements of the agreement. (Source: Specific FTA texts and implementing regulations).