HS 293148 3,9-Dimethyl-2,4,8,10-tetraoxa-3,9-diphosphaspiro[5.5] undecane 3,9-dioxide

Quick Answer: HS code 293148 specifically covers 3,9-Dimethyl-2,4,8,10-tetraoxa-3,9-diphosphaspiro[5.5]undecane 3,9-dioxide, a complex organo-phosphorus compound. This chemical is primarily used as an intermediate in various industrial applications, including as a ligand in catalysis or in the synthesis of specialized polymers and flame retardants. Importers and customs brokers should note the varying duty rates: the UK applies a 6.00% ad valorem duty, while the EU's TARIC system shows 6.50%. In the US, the Most Favored Nation (MFN) rate is 3.7% ad valorem, with numerous Free Trade Agreement (FTA) preferential rates available (e.g., for goods from Australia, Korea, Mexico, etc.), and a Column 2 rate of 25%. Verifying product origin for FTA eligibility is crucial to optimize duty costs.

What Are the Import Duty Rates?

🇬🇧 United Kingdom

Code MFN Preferential Unit
2931480000 6.00 % — —

🇪🇺 European Union (TARIC)

Code MFN Preferential Unit
2931480000 6.50 % — —

🇺🇸 United States (HTSUS)

Code MFN Preferential Unit
2931480000 3.7% 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 2931.48?

Imports of 3,9-Dimethyl-2,4,8,10-tetraoxa-3,9-diphosphaspiro[5.5] undecane 3,9-dioxide 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 to Classify This HS Code?

What products does HS 293148 cover?

This subheading covers 3,9-Dimethyl-2,4,8,10-tetraoxa-3,9-diphosphaspiro[5.5]undecane 3,9-dioxide, a specific organo-phosphorus compound. As defined by the World Customs Organization (WCO) Harmonized System (HS) Nomenclature and reflected in national tariffs such as the USITC Harmonized Tariff Schedule of the United States (HTSUS) and the EU TARIC, this chemical is precisely identified by its unique chemical structure and name. It is a complex organic compound containing both phosphorus and oxygen within a spirocyclic ring system, falling under Heading 2931 which encompasses other organo-inorganic compounds containing non-metals or metals (other than carbon or hydrogen only compounds of heading 2901 or 2902). Its classification is based on its specific chemical identity rather than its end-use.

What falls outside HS 293148?

The following products are excluded from HS 293148: other organo-phosphorus compounds that do not possess the exact chemical structure of 3,9-Dimethyl-2,4,8,10-tetraoxa-3,9-diphosphaspiro[5.5]undecane 3,9-dioxide. For instance, simpler organo-phosphorus compounds like trimethyl phosphate would be classified under other subheadings within Heading 2931, such as 2931.39. Other spiro compounds without phosphorus, or phosphorus compounds without the specific spiro structure, would also be excluded. Furthermore, mixtures containing this compound, but not consisting solely or essentially of it, might be classified elsewhere based on the General Interpretative Rules (GRI), particularly GRI 3(b) if they are mixtures or composite goods.

What are common classification mistakes for HS 293148?

A common error is misclassifying similar-sounding or structurally related organo-phosphorus compounds under HS 293148, failing to recognize the precise chemical specificity required for this subheading. Importers might mistakenly classify other spirocyclic organo-phosphorus compounds or even simpler phosphorus-containing organic compounds here, overlooking the exact "3,9-Dimethyl-2,4,8,10-tetraoxa-3,9-diphosphaspiro[5.5]undecane 3,9-dioxide" definition. This often stems from a lack of detailed chemical analysis or an over-reliance on trade names rather than the systematic chemical nomenclature. Adherence to General Interpretative Rule (GRI) 1, which states that classification is determined according to the terms of the headings and any relative section or chapter notes, is crucial to avoid such errors.

How should importers classify products under HS 293148?

The correct procedure for classifying products under HS 293148 involves a rigorous chemical identification process. Importers and customs brokers must obtain a Certificate of Analysis (CoA) or equivalent documentation from the manufacturer, clearly stating the precise chemical name, CAS number, and molecular structure. This documentation should unequivocally confirm the product is 3,9-Dimethyl-2,4,8,10-tetraoxa-3,9-diphosphaspiro[5.5]undecane 3,9-dioxide. Cross-referencing with the WCO Explanatory Notes for Heading 2931 and consulting national tariff schedules (e.g., USITC HTSUS, EU TARIC, UK Trade Tariff) for any specific national interpretations or rulings is also essential. If doubt persists, seeking a binding tariff information (BTI) ruling from the relevant customs authority is the most prudent course of action to ensure compliance and avoid potential penalties.

Which HS Codes Are Related?

HS 293146 HS 293147 HS 293143 HS 293142 HS 293144 HS 293145

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

FAQ

What is the Most Favored Nation (MFN) import duty rate for HS code 2931.48 in the United States, and how does it compare to other major markets?

For HS code 2931.48, '3,9-Dimethyl-2,4,8,10-tetraoxa-3,9-diphosphaspiro[5.5]undecane 3,9-dioxide', the current MFN (Normal Trade Relations) import duty rate in the United States is 3.7% ad valorem, as per the Harmonized Tariff Schedule of the United States (HTSUS) General Note 3(b). In comparison, the European Union's TARIC database indicates a common customs tariff duty rate of 6.50% ad valorem for this subheading, while the UK Global Tariff (UKGT) also lists a 6.50% ad valorem rate. Importers should always verify the current rates directly with the USITC HTSUS, EU TARIC, or UK Trade Tariff for the most up-to-date information, as rates are subject to change.

Are there any preferential duty rates available for HS code 2931.48 under U.S. Free Trade Agreements or special programs?

Yes, preferential duty treatment may be available for HS code 2931.48 when imported into the United States, depending on the country of origin and applicable trade agreements. Based on the provided sample, this product may qualify for a 'Free' duty rate under various programs and Free Trade Agreements (FTAs) such as those with 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). To claim preferential duty, importers must ensure the product meets the specific Rules of Origin criteria outlined in the respective trade agreement and possess the required documentation, such as a Certificate of Origin. It is crucial to consult the specific FTA text and the HTSUS General Notes for detailed requirements.

What are the key classification criteria for '3,9-Dimethyl-2,4,8,10-tetraoxa-3,9-diphosphaspiro[5.5]undecane 3,9-dioxide' under HS 2931.48?

HS code 2931.48 falls under Chapter 29 of the Harmonized System, which covers 'Organic chemicals.' Specifically, it is located within heading 2931, 'Other organo-inorganic compounds.' The classification criteria for '3,9-Dimethyl-2,4,8,10-tetraoxa-3,9-diphosphaspiro[5.5]undecane 3,9-dioxide' under subheading 2931.48 are based on its precise chemical structure as an organo-phosphorus compound with a defined spiro[5.5]undecane ring system and dioxide functionality. This subheading specifically covers 'Organo-phosphorus compounds: Other.' Importers must ensure that the chemical name and structure precisely match the description to avoid misclassification. Laboratory analysis or a chemical abstract service (CAS) number can often aid in confirming the exact chemical identity for classification purposes, referencing the WCO Explanatory Notes for Chapter 29 for further guidance.

What documentation is typically required for importing HS code 2931.48, and are there any specific regulatory considerations for this chemical?

Standard import documentation for HS code 2931.48, '3,9-Dimethyl-2,4,8,10-tetraoxa-3,9-diphosphaspiro[5.5]undecane 3,9-dioxide,' includes a commercial invoice, packing list, bill of lading or air waybill, and potentially a Certificate of Origin if preferential duty rates are claimed. Given that this is an organic chemical, importers should also be prepared to provide a Material Safety Data Sheet (MSDS) or Safety Data Sheet (SDS) to customs authorities, as well as to comply with any domestic chemical control regulations. In the U.S., this could involve compliance with the Toxic Substances Control Act (TSCA) administered by the Environmental Protection Agency (EPA), requiring specific import certifications (e.g., TSCA Section 13 certification). Importers should verify with relevant national agencies for any specific permits, licenses, or reporting requirements applicable to the chemical's composition and intended use.