3913 · Natural polymers (for example, alginic acid) and modified natural polymers (for example, hardened proteins, chemical derivatives of natural rubber), not elsewhere specified or included, in primary forms:
This is a category heading rather than a rate line — pick one of the codes below to see its full duty stack.
Subordinate codes (2)
| Code | Description |
|---|---|
| 3913.10.00.00 | Alginic acid, its salts and esters |
| 3913.90 | Other: |
Frequently asked
- What does 3913 cover?
- Natural polymers (for example, alginic acid) and modified natural polymers (for example, hardened proteins, chemical derivatives of natural rubber), not elsewhere specified or included, in primary forms:. This is a heading-level category with several subordinate codes — open one to see its full duty breakdown.
- Where does this data come from?
- Codes and MFN base rates come from the full USITC HTS 2026 Rev.11 export. Section 301/232/122 surcharge mappings are approximated pending code-level review. Every rate carries a source_url and effective_from, so you can trace it back to the controlling notice.