Sulfonamides — HTS 2935
Sulfonamides
Chapter 29 › Heading 2935
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 2935 is a 4-digit product category for sulfonamides, a class of organic chemical compounds that contain a sulfonamide group. It generally groups chemical substances and preparations classified by their chemical identity, rather than by their brand name, intended retail use, or country of origin. Products in this heading may be sold as laboratory, industrial, pharmaceutical, or other chemical materials, but their exact classification depends on the tariff wording and the product’s composition.
To narrow heading 2935 to a specific 8-digit HTS code, first identify the precise chemical substance or type named in the subheadings. Check the product’s molecular identity, whether it is a defined compound or a mixture/preparation, its form and purity, and any exclusions or special wording in the tariff schedule. Use the official HTS description and the General Rules of Interpretation; a customs broker or classification specialist may be needed when the chemistry or tariff scope is unclear.
What to check
- Obtain the product’s exact chemical name, CAS Registry Number, molecular formula, and specification or safety data sheet.
- Determine whether the item is a single chemically defined sulfonamide or a mixture, formulation, salt, solution, or preparation.
- Read every lower-level subheading under 2935 and match the product to the most specific description, including any material or chemical-type distinctions.
- Check the HTS legal notes, chapter notes, exclusions, and unit-of-quantity requirements before selecting the 8-digit code.
- Document the classification reasoning and request broker or customs guidance if the product could fit more than one chemical description.
HTS heading 2935 summary
Sulfonamides is a 4-digit product category containing 5 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 |
|---|---|
| 2935.90 | Other |
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 |
|---|---|---|---|---|
| 2935.10.00.00 👉 | N-Methyl perfluorooctane sulfonamide | 6.5% | Free | 15.4¢/kg + 57.5% |
| 2935.20.00.00 👉 | N-Ethyl perfluorooctane sulfonamide | 6.5% | Free | 15.4¢/kg + 57.5% |
| 2935.30.00.00 👉 | N-Ethyl -N-(2-hydroxyethyl)perfluorooctane sulfonamide | 6.5% | Free | 15.4¢/kg + 57.5% |
| 2935.40.00.00 👉 | N-(2-hydroxyethyl)-N-methyl perfluorooctane sulfonamide | 6.5% | Free | 15.4¢/kg + 57.5% |
| 2935.50.00.00 👉 | Other perfluorooctane sulfonamides | 6.5% | Free | 15.4¢/kg + 57.5% |
"Special" shows the free-trade-agreement rate; open a code to see exactly which countries qualify.
Common questions
What products fall under HTS heading 2935?
Sulfonamides. 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.