# United States tariff lines under HS 3913.90

> The United States tariff splits HS 3913.90 (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) into 4 national lines: 3913.90.10.00 (chemical derivatives of natural rubber), 3913.90.20.15 (xanthan gum), 3913.90.20.90 (other) and 3913.90.50.00 (other). The general (MFN) duty differs by line: free on 3913.90.10.00, 5.8% on 3913.90.20.15, 5.8% on 3913.90.20.90 and 6.5% on 3913.90.50.00.

Source: https://border.bot/countries/united-states/hs-codes/391390
Last updated: 9 October 2026

[Countries](https://border.bot/countries) / [United States](https://border.bot/countries/united-states) / [Chapter 39](https://border.bot/countries/united-states/hs-codes/39) / [3913.90](https://border.bot/countries/united-states/hs-codes/391390)

## Key facts

- HS subheading: [3913.90](https://border.bot/hs-codes/391390)
- National lines: 4
- Tariff: [United States](https://border.bot/countries/united-states)
- Chapter: 39: Plastics and articles thereof

## United States lines under 3913.90

The United States tariff splits HS 3913.90 (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) into 4 national lines: 3913.90.10.00 (chemical derivatives of natural rubber), 3913.90.20.15 (xanthan gum), 3913.90.20.90 (other) and 3913.90.50.00 (other).

The general (MFN) duty differs by line: free on 3913.90.10.00, 5.8% on 3913.90.20.15, 5.8% on 3913.90.20.90 and 6.5% on 3913.90.50.00.

- [3913.90.10.00](https://border.bot/countries/united-states/hs-codes/3913901000) Other, Chemical derivatives of natural rubber. Duty (MFN): free
- [3913.90.20.15](https://border.bot/countries/united-states/hs-codes/3913902015) Other, Polysaccharides and their derivatives, Xanthan gum. Duty (MFN): 5.8%
- [3913.90.20.90](https://border.bot/countries/united-states/hs-codes/3913902090) Other, Polysaccharides and their derivatives, Other. Duty (MFN): 5.8%
- [3913.90.50.00](https://border.bot/countries/united-states/hs-codes/3913905000) Other, Other. Duty (MFN): 6.5%

## In other countries

No other national tariff on border.bot has live lines under 3913.90 yet.

- [The Harmonized System text for 3913.90](https://border.bot/hs-codes/391390)

- Previous subheading: [3913.10](https://border.bot/countries/united-states/hs-codes/391310) 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
- Next subheading: [3914.00](https://border.bot/countries/united-states/hs-codes/391400) Ion-exchangers based on polymers of headings 3901 to 3913, in primary forms

## Frequently asked questions

### How many national tariff lines does the United States tariff have under HS 3913.90?

The United States tariff splits HS 3913.90 (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) into 4 national lines: 3913.90.10.00 (chemical derivatives of natural rubber), 3913.90.20.15 (xanthan gum), 3913.90.20.90 (other) and 3913.90.50.00 (other).

### What is the duty on HS 3913.90 in the United States?

The general (MFN) duty differs by line: free on 3913.90.10.00, 5.8% on 3913.90.20.15, 5.8% on 3913.90.20.90 and 6.5% on 3913.90.50.00.

## Sources and updates

The tariff lines for the United States come from border.bot release 1 (edition 2026HTSRev21), read from the publisher’s files, and have been live since 9 October 2026.

The duty rates for the United States come from border.bot release 1 (edition 2026HTSRev21), read from the publisher’s files, and have been live since 9 October 2026.

The trade programmes for the United States come from border.bot release 1 (edition 2026HTSRev21), read from the publisher’s files, and have been live since 9 October 2026.

This page was last updated on 9 October 2026.

Guidance from published tariff data, not a binding ruling. For a decision customs must follow, apply to the destination’s customs authority for a binding tariff ruling.

Official source files:

- https://hts.usitc.gov/reststop/exportList?from=0000000000&to=9999999999&format=CSV&styles=false

Machine-readable: https://border.bot/countries/united-states/hs-codes/391390.json