HS 283330 Alums
Quick Answer: HS code 283330 covers "Alums," which are double sulfates of a monovalent cation (like potassium or ammonium) and a trivalent cation (like aluminum or chromium). These inorganic chemical compounds are commonly used in water purification, as mordants in dyeing, and in various industrial applications. Importers and customs brokers should note the varying duty rates across major jurisdictions. In the UK, the general duty rate is 4.00% ad valorem. The EU applies a general rate of 5.50% ad valorem. For the US, the Most Favored Nation (MFN) rate is 1.6% ad valorem, but certain alums may face a 25% rate under specific trade measures. Additionally, many US Free Trade Agreement (FTA) partners, including Australia, Canada, Mexico, and South Korea, benefit from a "Free" duty rate, offering significant cost savings for eligible goods. Always verify the specific alum type and country of origin for accurate classification and duty assessment.
What Are the Import Duty Rates?
🇬🇧 United Kingdom
| Code | MFN | Preferential | Unit |
|---|---|---|---|
| 2833300000 | 4.00 % | — | — |
🇪🇺 European Union (TARIC)
| Code | MFN | Preferential | Unit |
|---|---|---|---|
| 2833300000 | 5.50 % | — | — |
🇺🇸 United States (HTSUS)
| Code | MFN | Preferential | Unit |
|---|---|---|---|
| 2833300000 | 1.6% | 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 2833.30?
Imports of Alums 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 283330 cover?
This subheading covers "Alums," which are double sulfates of a monovalent cation (like potassium or ammonium) and a trivalent cation (like aluminum or chromium). Specifically, the Harmonized System Explanatory Notes (HSEN) to Heading 2833 clarify that alums are complex salts, typically hydrated, characterized by their specific chemical structure and properties. Examples include potassium aluminum sulfate (potash alum, KAl(SO₄)₂·12H₂O) and ammonium aluminum sulfate (ammonium alum, NH₄Al(SO₄)₂·12H₂O). These substances are widely used in water purification, tanning, dyeing, and as mordants. The USITC Harmonized Tariff Schedule (HTS) and EU TARIC both align with this WCO definition, ensuring consistent global classification for these specific chemical compounds.
What falls outside HS 283330?
The following products are excluded from HS 283330: simple sulfates of aluminum, such as aluminum sulfate (Al₂(SO₄)₃), which are classified under HS 28332200. While aluminum sulfate is often colloquially referred to as "alum" in some industrial contexts due to similar applications, it lacks the double sulfate structure characteristic of true alums as defined by the HS. Similarly, other double sulfates that do not contain aluminum as the trivalent cation, or do not fit the specific "alum" structure, would be classified elsewhere, often under other subheadings of 2833 or other chapters depending on their specific chemical composition. For instance, chromium potassium sulfate (chrome alum) is also an alum and would fall here, but other complex sulfates not meeting the definition would be excluded.
What are common classification mistakes for HS 283330?
A common error is misclassifying simple aluminum sulfate (Al₂(SO₄)₃) under HS 283330 instead of its correct subheading, HS 28332200. This mistake often arises from the colloquial use of "alum" to refer to aluminum sulfate, particularly in water treatment industries. However, according to the WCO HS nomenclature and the General Interpretative Rule (GRI) 1, classification must be determined by the terms of the headings and any relative section or chapter notes, and then according to the subheadings. The specific chemical structure of a double sulfate is crucial for 283330, distinguishing it from the simple salt. Importers must verify the exact chemical composition, not just the common name, to avoid misclassification and potential penalties.
How should importers classify products under HS 283330?
The correct procedure for classifying products under HS 283330 involves a meticulous review of the chemical composition and structure. Importers and customs brokers should first obtain the precise chemical name and formula for the product, ideally from a Certificate of Analysis (CoA) or Safety Data Sheet (SDS). Verify that the product is indeed a double sulfate of a monovalent and a trivalent cation, specifically meeting the definition of an "alum" as outlined in the HS Explanatory Notes to Heading 2833. If there is any ambiguity, consider requesting a binding ruling from the relevant customs authority (e.g., CBP in the US, HMRC in the UK, or national customs authorities in the EU) to ensure compliance and avoid potential duty discrepancies or penalties.
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FAQ
What is the Most Favored Nation (MFN) import duty rate for 'Alums' (HS 2833.30) into the United States, and are there any significant preferential rates?
For imports into the United States, 'Alums' classified under HS 2833.30.00 typically face a Most Favored Nation (MFN) duty rate of 4.0% ad valorem, as per the Harmonized Tariff Schedule of the United States (HTSUS). However, many U.S. free trade agreements and preference programs offer significantly lower or duty-free treatment. For instance, imports from countries like 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) are eligible for duty-free entry under various Free Trade Agreements (FTAs). Additionally, certain developing countries may qualify for duty-free treatment under programs like the Generalized System of Preferences (GSP), if applicable to this tariff line. Importers should verify the specific program indicator (e.g., 'A', 'A*', 'D', 'E', 'J', 'K', 'L', 'P', 'P+', 'R') in the HTSUS for their country of origin.
What are the key classification criteria for 'Alums' under HS 2833.30, and how does it differentiate from other sulfates?
HS 2833.30 specifically covers 'Alums,' which are double sulfates of aluminum and another metal (usually an alkali metal like potassium or ammonium). The primary classification criterion is the chemical composition confirming the presence of both aluminum sulfate and another metal sulfate in a specific crystalline structure. This sub-heading is distinct from other sulfates found in HS 2833 due to its characteristic double salt structure. For example, simple aluminum sulfates (not alums) would typically fall under HS 2833.22.00. Customs authorities, such as the U.S. Customs and Border Protection (CBP) or the EU TARIC system, rely on chemical analysis and product specifications to confirm the exact nature of the sulfate to ensure correct classification. Importers should provide detailed chemical descriptions and CAS numbers.
What documentation is typically required by customs authorities for the importation of 'Alums' under HS 2833.30?
For the importation of 'Alums' under HS 2833.30, standard customs documentation includes a commercial invoice, packing list, and bill of lading or air waybill. Crucially, a Certificate of Analysis (CoA) or product specification sheet detailing the chemical composition, purity, and CAS number is highly recommended to substantiate the HS classification. If claiming preferential duty rates under a Free Trade Agreement (FTA) or other preference program, a valid Certificate of Origin (e.g., a Free Trade Agreement Certificate of Origin) is mandatory. For certain chemical substances, additional regulatory compliance documentation might be required by agencies like the Environmental Protection Agency (EPA) under TSCA (Toxic Substances Control Act) in the U.S., or REACH (Registration, Evaluation, Authorisation and Restriction of Chemicals) in the EU, though 'Alums' are generally well-established chemicals. Importers should confirm specific country-of-import requirements.
How do common trade agreements, such as those with the EU or UK, impact the duty rates for 'Alums' (HS 2833.30)?
The duty rates for 'Alums' (HS 2833.30) are significantly impacted by various trade agreements. For imports into the European Union (EU) from countries with which the EU has an FTA, 'Alums' often qualify for duty-free treatment. For example, under the EU-Korea FTA, goods originating in Korea would typically enter the EU duty-free. Similarly, the UK Global Tariff (UKGT) for HS 2833.30.00.00 generally lists a Most Favored Nation (MFN) rate of 5.5% ad valorem, but offers duty-free access for goods originating from countries with which the UK has a Free Trade Agreement (e.g., EU, Australia, Japan, Korea). Importers must ensure they have a valid proof of origin (e.g., EUR.1 certificate, origin declaration, or statement on origin) to claim these preferential rates. Without proper origin documentation, the MFN rate will apply.