HS 290431 Perfluorooctane sulphonic acid, its salts and perfluorooctane sulphonyl fluoride
Quick Answer: HS code 290431 covers Perfluorooctane sulphonic acid (PFOS), its salts, and perfluorooctane sulphonyl fluoride (PFOSF). These are synthetic organic fluorine compounds primarily used in specialized industrial applications, such as surfactants, repellents, and fire-fighting foams, though their use is increasingly restricted due to environmental concerns. For importers and exporters, understanding the duty rates is crucial. The UK Trade Tariff indicates a 0.00% duty rate. The EU TARIC applies a 5.50% ad valorem duty. In the United States, the general Most Favored Nation (MFN) duty rate is 3.7% ad valorem, with many countries benefiting from a 0.00% rate under various Free Trade Agreements (e.g., A, AU, CL, KR). However, goods from certain countries may face a 25% duty under specific trade measures. Importers should verify origin and applicable trade programs. Additionally, compliance with environmental regulations regarding PFOS is paramount, as many jurisdictions restrict or prohibit its manufacture, use, and import due to its persistent organic pollutant (POP) status under the Stockholm Convention.
What Are the Import Duty Rates?
🇬🇧 United Kingdom
| Code | MFN | Preferential | Unit |
|---|---|---|---|
| 2904310000 | 0.00 % | — | — |
🇪🇺 European Union (TARIC)
| Code | MFN | Preferential | Unit |
|---|---|---|---|
| 2904310000 | 5.50 % | — | — |
🇺🇸 United States (HTSUS)
| Code | MFN | Preferential | Unit |
|---|---|---|---|
| 2904310000 | 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 2904.31?
Imports of Perfluorooctane sulphonic acid, its salts and perfluorooctane sulphonyl fluoride 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 to Classify This HS Code?
What products does HS 290431 cover?
This subheading covers perfluorooctane sulphonic acid (PFOS), its salts, and perfluorooctane sulphonyl fluoride (PFOSF), as specifically defined within the Harmonized System (HS) Nomenclature under Heading 2904. These are organo-sulphur compounds, specifically derivatives of hydrocarbons containing only fluorine, chlorine, bromine, or iodine atoms, and sulphonic acid groups. The scope is precise, encompassing the acid itself, any of its various salts (e.g., potassium perfluorooctane sulphonate), and the related sulphonyl fluoride. This classification aligns with the official definitions provided by the World Customs Organization (WCO) and reflected in national tariffs such as the USITC Harmonized Tariff Schedule (HTS) and the EU TARIC system.
What falls outside HS 290431?
The following products are excluded from HS 290431: perfluorooctanoic acid (PFOA) and its salts, which are carboxylic acids and are classified elsewhere, typically under HS 2915. Also excluded are other perfluorinated compounds that do not possess the specific perfluorooctane sulphonic acid structure or its sulphonyl fluoride derivative, such as shorter-chain perfluoroalkyl sulphonic acids (e.g., perfluorohexane sulphonic acid) or longer-chain variants. Polymers incorporating PFOS or its derivatives as monomers, or articles containing PFOS, are also excluded, as Chapter 29 covers separate chemically defined organic compounds, not mixtures, preparations, or articles. For instance, a fire-fighting foam containing PFOS would be classified as a preparation, not under this chemical subheading.
What are common classification mistakes for HS 290431?
A common error is misclassifying other perfluorinated compounds, particularly perfluorooctanoic acid (PFOA) and its derivatives, under HS 290431 due to their similar names and environmental concerns. PFOA is a carboxylic acid, not a sulphonic acid, and thus falls under a different chemical functional group and HS heading (e.g., HS 2915). Another mistake involves classifying mixtures or preparations containing PFOS, such as certain surfactants or fire-fighting foams, directly under this subheading. According to General Interpretative Rule (GRI) 3(b), mixtures are generally classified by the character-imparting component or under the heading for mixtures, not as the pure chemical compound. Importers must ensure the product is a separate chemically defined organic compound as required by Chapter 29 Note 1.
How should importers classify products under HS 290431?
The correct procedure for classifying products under HS 290431 requires meticulous attention to chemical identity. Importers and customs brokers should first verify that the product is indeed perfluorooctane sulphonic acid, one of its salts, or perfluorooctane sulphonyl fluoride, based on its chemical name, CAS number, and structural formula. Reviewing the Safety Data Sheet (SDS) and Certificate of Analysis (CoA) is crucial to confirm the exact chemical composition and purity. If the product is a mixture or preparation containing PFOS, it should not be classified here but rather under the appropriate heading for mixtures or preparations, applying GRI 3. Consulting the WCO Explanatory Notes for Chapter 29 and specific national tariff guidance (e.g., USITC HTS General Notes, EU TARIC classification regulations) will provide definitive clarification and prevent misclassification.
Which HS Codes Are Related?
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FAQ
What is the Most Favored Nation (MFN) import duty rate for HS 2904.31 in the United States?
For Harmonized System (HS) subheading 2904.31, 'Perfluorooctane sulphonic acid, its salts and perfluorooctane sulphonyl fluoride,' the current Most Favored Nation (MFN) general duty rate in the United States, as per the Harmonized Tariff Schedule of the United States (HTSUS), is 3.7% ad valorem. This rate applies to imports from countries that do not have a specific preferential trade agreement or special program with the U.S. or are not subject to punitive tariffs.
Are there any preferential duty rates available for HS 2904.31 under U.S. Free Trade Agreements?
Yes, preferential duty rates are available for HS 2904.31 under various U.S. Free Trade Agreements (FTAs). For eligible imports originating from countries such as Australia (AU), Bahrain (BH), Chile (CL), Colombia (CO), Israel (IL), Jordan (JO), Korea (KR), Morocco (MA), Oman (OM), Panama (PA), Peru (PE), and Singapore (SG), the duty rate is 'Free' (0.00% ad valorem). Importers must ensure they meet the rules of origin requirements specified in the respective FTA and provide proper documentation, such as a certificate of origin, to claim these preferential rates. Additionally, other programs like the Generalized System of Preferences (GSP) or Caribbean Basin Initiative (CBI) might offer duty-free treatment for eligible developing countries, though their applicability to this specific chemical depends on the product's origin and program status.
What are the key classification criteria for HS 2904.31, and how does it differ from other organo-sulphur compounds?
HS 2904.31 specifically covers 'Perfluorooctane sulphonic acid, its salts and perfluorooctane sulphonyl fluoride.' The key classification criteria revolve around the precise chemical structure: it must be a perfluorinated compound containing an eight-carbon chain (octane) with a sulphonic acid group, its salt, or a sulphonyl fluoride group. This distinguishes it from other organo-sulphur compounds classified elsewhere in Chapter 29 (e.g., other sulphonated, nitrated, or nitrosated derivatives of hydrocarbons) by its specific perfluorinated structure and the presence of the C8 chain. Importers should have detailed chemical specifications, including CAS numbers and structural formulas, to ensure accurate classification, as misclassification can lead to incorrect duty assessments or regulatory non-compliance. The World Customs Organization (WCO) Explanatory Notes for Chapter 29 provide further guidance on the scope of these chemical classifications.
Are there any specific documentation requirements or regulatory considerations for importing Perfluorooctane sulphonic acid (PFOS) under HS 2904.31?
Given that Perfluorooctane sulphonic acid (PFOS) and its derivatives are persistent organic pollutants, their import under HS 2904.31 is subject to significant international and national regulatory controls. Importers should be aware of potential restrictions or prohibitions under the Stockholm Convention on Persistent Organic Pollutants, which aims to reduce and eliminate the production, use, and release of POPs. In the United States, the Environmental Protection Agency (EPA) regulates these substances under the Toxic Substances Control Act (TSCA). Importers may need to provide specific documentation, such as pre-manufacture notices (PMN), significant new use notices (SNUN), or certifications of compliance with EPA regulations. It is crucial for importers and customs brokers to verify the latest regulatory requirements with relevant environmental agencies prior to importation to ensure compliance and avoid penalties or shipment delays. Material Safety Data Sheets (MSDS) or Safety Data Sheets (SDS) are always required for chemical imports.