Reaction initiators — HTS 3815
Reaction initiators, reaction accelerators and catalytic preparations, not elsewhere specified or included
Chapter 38 › Heading 3815
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 3815 covers certain chemical products used to start, speed up, or help control chemical reactions. It generally includes reaction initiators, reaction accelerators, and catalytic preparations when they are not more specifically described in another tariff heading. These products may be supplied as individual chemicals, mixtures, or preparations, depending on the applicable subheading.
The 4-digit heading is only a broad category, not the final classification. To reach the correct 8-digit HTSUS code, follow the subheadings and compare the product’s material, chemical composition, physical form, and intended function. The lower-level provisions commonly distinguish products by type or principal material, so the exact ingredients and technical use matter. Confirm the result against the current HTSUS and, when the classification is uncertain, seek a customs broker’s or binding-ruling guidance.
What to check
- Read the complete product specification, including the active ingredient, carrier or support material, concentration, and physical form.
- Determine whether the product is intended to initiate a reaction, accelerate it, or act as a catalyst, and document its principal function.
- Check whether another HTS heading describes the product more specifically before using heading 3815; the phrase “not elsewhere specified or included” matters.
- Compare the product with every applicable 6-digit and 8-digit subheading, using the wording and legal notes rather than relying only on a commercial product name.
- Verify the classification against the current HTSUS and keep safety data sheets, technical datasheets, formulation information, and supplier descriptions to support the decision.
HTS heading 3815 summary
Reaction initiators is a 4-digit product category containing 3 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 |
|---|---|
| 3815.90 | 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 |
|---|---|---|---|---|
| 3815.11.00.00 👉 | With nickel or nickel compounds as the active substance | Free | — | 25% |
| 3815.12.00 👉 | With precious metal or precious metal compounds as the active substance | Free | — | 25% |
| 3815.19.00.00 👉 | Other | Free | — | 25% |
"Special" shows the free-trade-agreement rate; open a code to see exactly which countries qualify.
Common questions
What products fall under HTS heading 3815?
Reaction initiators, reaction accelerators and catalytic preparations, not elsewhere specified or included. 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.