HS 390721 Other polyethers

Quick Answer: Other polyethers imported under HS 390721 enter the UK at 6.00%, the EU at 6.50%, and the US with a complex tariff structure including a 6.5% ad valorem rate for many trading partners and a specific duty of 2.2¢/kg + 33.5% for others. This classification covers polyethers that are not specifically listed elsewhere in Chapter 39 of the Harmonized System. These are polymers formed by the reaction of epoxides or by the polymerization of other cyclic ethers, often used as intermediates in the production of polyurethanes, surfactants, and lubricants. Importers should carefully verify the specific type of polyether and the origin country to determine the applicable duty rate, as the US tariff, in particular, shows significant variation. CustomTariffs aggregates this information to assist trade professionals.

What Are the Import Duty Rates?

🇬🇧 United Kingdom

Code MFN Preferential Unit
3907210000 6.00 % — —

🇪🇺 European Union (TARIC)

Code MFN Preferential Unit
3907210000 6.50 % — —

🇺🇸 United States (HTSUS)

Code MFN Preferential Unit
3907210000 6.5% Free (18 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 3907.21?

Imports of Other polyethers 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 15 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?

Trade Volume 2023

US$4.6M
ImportsExports

How to Classify This HS Code?

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What products does HS 390721 cover?

This subheading covers other polyethers, which are polymers containing ether linkages in their main chain. According to the World Customs Organization (WCO) Harmonized System Nomenclature, this category encompasses polyethers not specifically listed under other subheadings within Heading 3907. For instance, the US International Trade Commission (USITC) Harmonized Tariff Schedule (HTS) defines this as polyethers other than those of ethylene oxide and propylene oxide, which are classified elsewhere. These are typically synthetic polymers used as intermediates or in the production of various materials.

What falls outside HS 390721?

The following products are excluded from HS 390721: polyethers of ethylene oxide and propylene oxide, which are classified under HS 390720. Also excluded are polyacetals and other polyethers and epoxides, in primary forms, of heading 3907. This means that specific types of polyethers with distinct chemical structures or primary uses, such as those used in polyurethane production (often classified under 3907.20.00 in the US HTS) or epoxy resins, are not included here. The key is the absence of ethylene oxide or propylene oxide repeating units in the main polymer chain for this specific subheading.

What are common classification mistakes for HS 390721?

A common error is misclassifying polyethers that contain ethylene oxide or propylene oxide repeating units under HS 390721, when they should be classified under HS 390720. This mistake often arises from a superficial understanding of the chemical structure. According to General Rule of Interpretation (GRI) 1, classification is determined by the terms of the headings and any relative section or chapter notes. Importers must carefully examine the product's chemical composition to ensure it aligns with the specific exclusions and inclusions of each subheading within Heading 3907.

How should importers classify products under HS 390721?

The correct procedure for classifying products under HS 390721 involves a thorough review of the product's technical data sheet and chemical composition. Importers and customs brokers must verify that the polymer is indeed a polyether and that it does not contain ethylene oxide or propylene oxide repeating units in its main chain. Consulting official tariff schedules, such as the USITC HTS or the EU TARIC database, and referencing the WCO HS Explanatory Notes is crucial for accurate determination. If uncertainty remains, seeking a binding ruling from customs authorities is recommended.

How is the duty calculated for products under HS 390721?

A shipment of 10,000 kilograms of polyether polyol, declared at a customs value of $25,000 USD, would attract a US duty of $1,250.00. This is calculated using the Most Favored Nation (MFN) duty rate of 5.0% ad valorem, applied to the declared customs value ($25,000 USD × 0.05 = $1,250.00). This specific duty rate is published in the USITC Harmonized Tariff Schedule for HS code 390721.00.00, assuming no other preferential duty rates apply.

Which trade agreements reduce duties for HS 390721?

Several free trade agreements may reduce the applicable duty rate for HS 390721. For instance, under the United States-Mexico-Canada Agreement (USMCA), originating goods may be admitted duty-free. Similarly, the European Union's Generalized Scheme of Preferences (GSP) can offer reduced or zero duties for originating goods from developing countries. To claim these preferences, a valid EUR.1 movement certificate or a self-certified origin statement, depending on the specific agreement and jurisdiction, is typically required. Countries like Mexico, Canada, and various GSP beneficiaries are key origins for such preferential trade.

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Which HS Codes Are Related?

HS 390791 HS 390710 HS 390761 HS 390730 HS 390729 HS 390950

Not the right code? Search all HS codes to find the correct tariff classification.

FAQ

What are the typical import duty rates for HS code 390721, 'Other polyethers'?

The import duty rates for HS code 390721 vary significantly by country and trade agreement. For example, under the U.S. Harmonized Tariff Schedule (USHTS), the Most Favored Nation (MFN) duty rate is typically 6.5% ad valorem. However, preferential rates under various trade agreements can be lower or even free. For instance, rates can be Free (A, AU, BH, CL, CO, D, E, IL, JO, K, KR, MA, OM, P, PA, PE, S, SG). It is crucial to consult the specific tariff schedule of the importing country for the applicable rate based on the origin of the goods and any relevant trade agreements. The USITC website is a primary resource for U.S. import duties.

How is the duty calculated for HS code 390721 when a specific duty rate is applied, such as '2.2¢/kg + 33.5%'?

When a duty rate is a combination of a specific duty (per unit of weight) and an ad valorem duty (based on value), the calculation involves two parts. For example, if a shipment of 1,000 kg of polyether with a declared value of $5,000 USD is subject to a rate of 2.2¢/kg + 33.5% ad valorem:

  1. Specific Duty: 1,000 kg * $0.022/kg = $22.00 USD
  2. Ad Valorem Duty: $5,000 USD * 0.335 (or 33.5%) = $1,675.00 USD

The total duty would be $22.00 + $1,675.00 = $1,697.00 USD. This type of combined duty is often seen in the U.S. tariff schedule for certain chemical products. Always verify the exact rate and currency with the official tariff database.

What are the key classification criteria to ensure a product is correctly classified under HS code 390721, 'Other polyethers'?

HS code 390721 falls under Chapter 39 of the Harmonized System, which covers 'Plastics and articles thereof'. Specifically, heading 3907 covers 'Polyacetals, other polyethers and epoxide resins, in primary forms; polycarbonates, alkyd resins, polyallyl esters and other polyesters, in primary forms'. Subheading 3907.21 specifically covers 'Other polyethers' that are not elsewhere specified within heading 3907. Classification relies on the chemical structure and form. Polyethers are polymers containing ether linkages (-R-O-R'-) in their main chain. 'Other polyethers' typically includes those not specifically enumerated in preceding subheadings, such as certain polyalkylene glycols (e.g., polyethylene glycol, polypropylene glycol) and their derivatives, provided they are in primary forms (e.g., powders, granules, flakes, liquids, pastes). Consult the Explanatory Notes to the Harmonized System for detailed definitions and guidance.

Which common trade agreements might provide preferential duty rates for HS code 390721, and what documentation is typically required?

Several trade agreements can offer preferential duty rates for HS code 390721. Examples include agreements between the U.S. and countries like Australia (AU), Bahrain (BH), Chile (CL), Colombia (CO), Israel (IL), Jordan (JO), South Korea (KR), Mexico (MA - under USMCA), Oman (OM), Panama (PA), Peru (PE), Singapore (SG), and others. The European Union's TARIC database and the UK Trade Tariff would list relevant agreements for those regions. To claim preferential treatment, importers typically need a 'Certificate of Origin' or a 'Declaration of Origin' issued by the exporter or producer, certifying that the goods meet the rules of origin stipulated in the specific trade agreement. The exact documentation requirements can vary by agreement and importing country, so it's essential to verify with the customs authorities of the destination country.