Dithionites and sulfoxylates — HTS 2831
Dithionites and sulfoxylates
Chapter 28 › Heading 2831
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 heading 2831 is a four-digit product category for dithionites and sulfoxylates. These are chemical substances grouped by their chemical identity and general composition, rather than by their brand name or intended commercial use alone. The heading can include different forms or types of these substances, subject to the detailed subheadings and any applicable classification rules.
To reach the correct 8-digit HTSUS code, start with the product’s exact chemical identity and composition, then follow the more specific subheadings under heading 2831. The deciding detail is usually the material or chemical type, and may also involve whether the product is pure, prepared, mixed, or presented in a particular form. Confirm the result against the current HTSUS wording, relevant chapter notes, and the product’s technical documents; a customs broker or binding ruling may be appropriate if the classification is uncertain.
What to check
- Obtain the product’s chemical name, formula, concentration, and safety data sheet before classifying it.
- Check whether the shipment is a single chemical substance or a mixture, preparation, solution, or formulation.
- Read every subheading under heading 2831 and match the product to the most specific description, rather than stopping at the four-digit heading.
- Compare the HTSUS text with the manufacturer’s specification sheet, invoice description, and packaging information.
- Ask a customs broker or request a binding classification ruling when the composition or applicable subheading is unclear.
HTS heading 2831 summary
Dithionites and sulfoxylates is a 4-digit product category containing 1 published product-code lines in this snapshot. A heading does not carry one universal duty rate; classification must be narrowed to the line matching the product facts.
How to find your code in this category
A heading is a product category. To get the exact duty, narrow from this 4-digit heading to a sub-category (usually by material), then open the 8-digit code that matches your product.
Open any code in the tables below to see its exact duty rate, a duty calculator (enter your shipment value → estimated duty and landed cost), the rate-change history chart, and the country-by-country breakdown (including Section 301/232 add-on duties).
Why you have to click in: a single category can contain products with very different duties. The rate depends on the specific product — its material and construction — and on the country of origin, and those only get pinned down at the 8-digit code level. That is why this page points you to codes instead of showing one rate for the whole category.
Sub-categories
| Code | Description |
|---|---|
| 2831.10 | Of sodium |
Product codes & duty rates
👇 Each row is a specific product code — click a blue code to open its full page with exact duty rates by country, the rate-history chart, and a duty calculator. 👉
| Code | Description | General (MFN) | Special | Column 2 |
|---|---|---|---|---|
| 2831.90.00.00 👉 | Other | 5.5% | Free | 35% |
"Special" shows the free-trade-agreement rate; open a code to see exactly which countries qualify.
Common questions
What products fall under HTS heading 2831?
Dithionites and sulfoxylates. To classify a specific item you must pick the matching sub-category and 8-digit code above; the right choice usually depends on the material and construction of the product.
How do I choose the right code within this category?
Start from the sub-categories (typically divided by material—for example cotton versus man-made fibers), then open the active 8- or 10-digit code that matches the product. When unsure, a licensed customs broker or a CBP binding ruling can confirm the classification.
Reference information only, not customs, legal, or classification advice. Confirm the current code and rate against the official HTS before you import.