HS 281121 Other inorganic oxygen compounds of non-metals

What products does HS 281121 cover?

This subheading covers silicon dioxide, commonly known as silica, which is an inorganic oxygen compound of the non-metal silicon. The scope specifically includes various forms of silica, such as fused silica, crystalline silica (e.g., quartz, cristobalite, tridymite), amorphous silica (e.g., silica gel, precipitated silica, fumed silica), and diatomite. According to the Harmonized System Nomenclature Explanatory Notes for Heading 2811, this subheading encompasses silicon dioxide in its chemically pure or commercially pure forms, provided it meets the general purity requirements for Chapter 28. The USITC Harmonized Tariff Schedule (HTS) and EU TARIC further confirm this specific classification for silicon dioxide, distinguishing it from other inorganic oxygen compounds of non-metals.

What falls outside HS 281121?

The following products are excluded from HS 281121: other inorganic oxygen compounds of non-metals that are not silicon dioxide, which are classified under HS 281129. For example, carbon dioxide (CO2) is classified under HS 281129, as are sulfur dioxide (SO2) and nitrogen oxides (e.g., N2O, NO2). Furthermore, natural sands containing silica, such as silica sands used in foundries or for glassmaking, are generally classified under Chapter 25, specifically HS 2505. Similarly, quartz and quartzite that are merely crushed or broken, but not chemically processed to isolate silicon dioxide, typically fall under HS 2506. Products that are mixtures or preparations containing silicon dioxide, but where silicon dioxide is not the predominant component or where the product has undergone further processing to become an article, would also be excluded and classified elsewhere based on their composition and function, often in later chapters.

What are common classification mistakes for HS 281121?

A common error is misclassifying other inorganic oxygen compounds of non-metals as silicon dioxide, or vice versa. Importers sometimes incorrectly classify carbon dioxide or sulfur dioxide under 281121, when these should be correctly assigned to HS 281129. Another frequent mistake involves classifying natural silica-containing materials, such as quartz sand (HS 2505) or natural quartz in its raw state (HS 2506), under 281121, failing to recognize that 281121 is specifically for the chemical compound silicon dioxide. This often occurs due to a misunderstanding of General Rule of Interpretation (GRI) 1, which dictates that classification is determined according to the terms of the headings and any relative section or chapter notes. Furthermore, highly processed articles where silicon dioxide is merely an ingredient, rather than the primary chemical substance, are often incorrectly placed here instead of their functional heading.

How should importers classify products under HS 281121?

The correct procedure for classifying products under HS 281121 involves first confirming the chemical identity of the product as silicon dioxide (SiO2). Importers and customs brokers should obtain a detailed chemical analysis or a Certificate of Analysis (CoA) from the manufacturer, clearly stating the chemical name, CAS number, and purity level. This documentation is crucial to demonstrate that the product is indeed silicon dioxide and meets the purity requirements for Chapter 28. Next, verify that the product is not a natural sand or rock that merely contains silica, but rather the isolated chemical compound. Consult the WCO Harmonized System Explanatory Notes for Heading 2811 and review relevant binding rulings from the US Customs and Border Protection (CBP) or similar authorities in the EU (TARIC) or UK (Trade Tariff) for comparable products. If the product is silicon dioxide, and not excluded by Chapter 28 notes, then HS 281121 is the appropriate classification, attracting a 3.5% ad valorem duty rate in the United States for most favored nation (MFN) countries.