HTS Chapter 28: Inorganic chemicals; compounds of precious metals and rare-earth metals
HTS Chapter 28 covers Inorganic chemicals; compounds of precious metals and rare-earth metals. Browse 40 published headings, then narrow to the active product line that matches the goods.
2026 HTS Rev 19 Synced Rules verified Operational
Written to help non-specialists understand this page. Rates, dates, and legal facts come from the official records above and on the linked source.
HTS Chapter 28 covers inorganic chemicals and certain related chemical elements and compounds. Examples include elemental halogens and other nonmetals, hydrogen and rare gases, alkali and alkaline-earth metals, inorganic acids, halides, sulfides, ammonia, hydroxides, peroxides, and certain metal oxides. The product’s chemical identity and composition are usually more important than its commercial use or brand name.
The Harmonized Tariff Schedule (HTS) is organized from broad to specific: chapter, heading, subheading, and usually a 10-digit statistical reporting number. Start with the product’s objectively documented substance and concentration, then compare the relevant heading and subheading descriptions, including legal notes and exclusions. A chapter 28 classification may depend on whether the product is chemically defined, mixed with other substances, in an aqueous solution, or prepared for a particular use. Borderline classifications may require a customs broker or a binding ruling from U.S. Customs and Border Protection.
What to check
- Confirm the exact chemical identity, formula, purity or concentration, physical form, and whether the product is a mixture, solution, alloy, or preparation.
- Read the heading and subheading text together with the General Rules of Interpretation, Chapter 28 notes, and any exclusions; do not classify from the product name alone.
- Check whether another HTS chapter covers the product because of its preparation, use, packaging, or inclusion in a more specific chemical category.
- Review the full 10-digit code and its statistical description, and keep supporting documents such as the safety data sheet, technical specifications, and supplier composition statement.
- After selecting the base HTS code, check current Chapter 99 provisions and other applicable measures, including additional duties, exclusions, quotas, licensing, or reporting requirements.
How to use this chapter
A chapter is the first classification level, not a duty rate. Choose the heading that describes the product, narrow by material, construction, use, or other legal distinctions, and verify the final line against the official HTS notes.
Heading list
| HTS code | Description | Linked 8-digit entries |
|---|---|---|
| 2801 | Fluorine, chlorine, bromine and iodine: | 0 |
| 2804 | Hydrogen, rare gases and other nonmetals: | 1 |
| 2805 | Alkali or alkaline-earth metals; rare-earth metals, scandium and yttrium, whether or not intermixed or interalloyed; mercury: | 1 |
| 2806 | Hydrogen chloride (Hydrochloric acid); chlorosulfuric acid: | 0 |
| 2809 | Diphosphorus pentaoxide; phosphoric acid;polyphosphoric acids, whether or not chemically defined: | 1 |
| 2811 | Other inorganic acids and other inorganic oxygen compounds of nonmetals: | 0 |
| 2812 | Halides and halide oxides of nonmetals: | 2 |
| 2813 | Sulfides of nonmetals; commercial phosphorus trisulfide: | 0 |
| 2814 | Ammonia, anhydrous or in aqueous solution: | 0 |
| 2815 | Sodium hydroxide (Caustic soda); potassium hydroxide (Caustic potash); peroxides of sodium or potassium: | 1 |
| 2816 | Hydroxide and peroxide of magnesium; oxides, hydroxides and peroxides, of strontium or barium: | 0 |
| 2818 | Artificial corundum, whether or not chemically defined; aluminum oxide; aluminum hydroxide: | 0 |
| 2819 | Chromium oxides and hydroxides: | 0 |
| 2820 | Manganese oxides: | 0 |
| 2821 | Iron oxides and hydroxides; earth colors containing 70 percent or more by weight of combined iron evaluated as Fe2O3: | 1 |
| 2824 | Lead oxides; red lead and orange lead: | 0 |
| 2825 | Hydrazine and hydroxylamine and their inorganic salts; other inorganic bases; other metal oxides, hydroxides and peroxides: | 2 |
| 2826 | Fluorides; fluorosilicates, fluoroaluminates and other complex fluorine salts: | 0 |
| 2827 | Chlorides, chloride oxides and chloride hydroxides; bromides and bromide oxides; iodides and iodide oxides: | 0 |
| 2828 | Hypochlorites; commercial calcium hypochlorite; chlorites; hypobromites: | 0 |
| 2829 | Chlorates and perchlorates; bromates and perbromates; iodates and periodates: | 0 |
| 2830 | Sulfides; polysulfides, whether or not chemically defined: | 0 |
| 2831 | Dithionites and sulfoxylates: | 0 |
| 2832 | Sulfites; thiosulfates: | 0 |
| 2833 | Sulfates; alums; peroxosulfates (persulfates): | 0 |
| 2834 | Nitrites; nitrates: | 0 |
| 2835 | Phosphinates (hypophosphites), phosphonates (phosphites) and phosphates; polyphosphates, whether or not chemically defined: | 0 |
| 2836 | Carbonates; peroxocarbonates (percarbonates); commercial ammonium carbonate containing ammonium carbamate: | 0 |
| 2837 | Cyanides, cyanide oxides and complex cyanides: | 1 |
| 2839 | Silicates; commercial alkali metal silicates: | 0 |
| 2840 | Borates; peroxoborates (perborates): | 1 |
| 2841 | Salts of oxometallic or peroxometallic acids: | 1 |
| 2842 | Other salts of inorganic acids or peroxoacids (including aluminosilicates whether or not chemically defined), other than azides: | 0 |
| 2843 | Colloidal precious metals; inorganic or organic compounds of precious metals, whether or not chemically defined; amalgams of precious metals: | 0 |
| 2844 | Radioactive chemical elements and radioactive isotopes (including the fissile or fertile chemical elements and isotopes) and their compounds; mixtures and residues containing these products: | 1 |
| 2845 | Isotopes other than those of heading 2844; compounds, inorganic or organic, of such isotopes, whether or not chemically defined: | 0 |
| 2846 | Compounds, inorganic or organic, of rare-earth metals, of yttrium or of scandium, or of mixtures of these metals: | 1 |
| 2849 | Carbides, whether or not chemically defined: | 0 |
| 2852 | Inorganic or organic compounds of mercury, whether or not chemically defined, excluding amalgams: | 0 |
| 2853 | Phosphides, whether or not chemically defined, excluding ferrophosphorous; other inorganic compounds (including distilled or conductivity water and water of similar purity); liquid air (whether or not rare gases have been removed); compressed air; amalgams, other than amalgams of precious metals: | 0 |
Linked measures
0 linked measure entries in the current snapshot.
Questions about HTS Chapter 28
What does HTS Chapter 28 cover?
HTS Chapter 28 covers Inorganic chemicals; compounds of precious metals and rare-earth metals. This page groups the chapter’s 4-digit headings; a shipment still needs the most specific active 8- or 10-digit line supported by the product facts.
Is HTS Chapter 28 a final product classification?
No. A chapter is a broad 2-digit category. Narrow it to the applicable heading and the most specific active statistical line before estimating duty or filing an entry.