HS Code 28.11 – Inorganic acids and other inorganic oxygen compounds of non-metals; n.e.c. in heading no. 2806 to 2810

HS code 2811 is a 4-digit heading in the Harmonized System that covers: Inorganic acids and other inorganic oxygen compounds of non-metals; n.e.c. in heading no. 2806 to 2810. Heading 2811 encompasses a diverse range of inorganic acids and other inorganic oxygen compounds of non-metals, specifically those not elsewhere specified (n.e.c.) in headings 2806 to 2810. This crucial 'n.e.c.' clause defines its scope, making it a residual category for a variety of essential industrial chemicals. It covers inorganic acids like hydrofluoric acid and hydrocyanic acid, along with key oxygen compounds of non-metals such as carbon dioxide, sulfur dioxide, silicon dioxide (silica), and hydrogen peroxide. These substances are fundamental building blocks in countless industrial processes, from manufacturing and agriculture to environmental applications and healthcare. For trade compliance professionals, understanding the precise scope and exclusions of 2811 is vital to avoid misclassification with the more specific acid headings (2806-2810) or with organic compounds. Its significance lies in classifying bulk commodities and specialized chemicals that form the backbone of modern industrial economies. Historically, the trade of these basic inorganic chemicals has been a barometer of industrial activity, reflecting demand for raw materials across various sectors. As part of Chapter 28, 'Inorganic Chemicals; Organic or Inorganic Compounds of Precious Metals, of Rare-Earth Metals, of Radioactive Elements or of Isotopes,' heading 2811 sits within a chapter dedicated to primary chemical substances, emphasizing its role as a foundational classification for materials that undergo further processing or are used directly in a multitude of applications.

Anhydrous hydrofluoric acid, aqueous hydrofluoric acid, liquid carbon dioxide, solid carbon dioxide (dry ice), gaseous carbon dioxide, liquid sulfur dioxide, gaseous sulfur dioxide, silicon dioxide (amorphous silica), hydrogen peroxide solution (various concentrations), anhydrous hydrogen cyanide, aqueous hydrogen cyanide, nitrous oxide (medical grade), nitrous oxide (industrial grade), carbon monoxide, selenium dioxide, tellurium dioxide, arsenic trioxide, boron trioxide (vitreous), diboron trioxide, phosphonic acid, metaphosphoric acid

Common misclassifications under 2811 often involve confusing it with more specific inorganic acid headings or organic compounds. Traders might mistakenly classify sulfuric acid (2807.00) or nitric acid (2808.00) under 2811, overlooking their dedicated headings. Another frequent error is classifying silicones or silicates (Chapter 29 or 28, respectively) as silicon dioxide from 2811, despite the latter being a simpler, uncompounded inorganic oxide. Similarly, some might confuse organic acids with inorganic acids, leading to classification under Chapter 29 instead of 2811. The key is to strictly adhere to the 'n.e.c.' clause and verify if a more specific heading exists for the inorganic acid or oxygen compound of a non-metal.

In 2025, the top exporters of HS code 2811 in UN Comtrade data were China ($1.5B, 26% of world exports), Germany ($683M) and Japan ($446M). World exports came to about $5.9B, adding countries' reported figures and partner-based estimates for those that did not report (UN Comtrade data). Countries that did not report 2025 data are estimated from partner records, which can understate them.

In 2025, the top importers of HS code 2811 in UN Comtrade data were the United States ($690M, 10% of world imports), China ($505M) and South Korea ($387M). World imports came to about $6.7B, adding countries' reported figures and partner-based estimates for those that did not report (UN Comtrade data). Countries that did not report 2025 data are estimated from partner records, which can understate them.

HS code 2811 is a 4-digit heading under Chapter 28 of the Harmonized System. The first 2 digits (28) identify the chapter, and digits 3-4 (11) specify the heading. This code contains multiple 6-digit subheadings for precise product classification.