Heading 3913

HTS code 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

Chapter
39 — Plastics
Tariff lines
5
General duty
General duty rates from 4.2% to 6.5%, with 1 duty-free line

Tariff lines under heading 3913

Full 10-digit codes with their general (MFN) duty rates. The correct line depends on the product's material, construction, and use.

HTS codeDescriptionGeneral rateUnit
3913.10.0000Alginic acid, its salts and esters (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)4.2%kg
3913.90.1000Chemical derivatives of natural rubber (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 > Other)Freekg
3913.90.2015Xanthan gum (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 > Other > Polysaccharides and their derivatives)5.8%kg
3913.90.2090Other (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 > Other > Polysaccharides and their derivatives)5.8%kg
3913.90.5000Other (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 > Other)6.5%kg

Documents required to import under 3913

Customs paperwork typically required to import these goods into the United States. Conditional items depend on shipment value, transport mode, or origin.

  • Commercial InvoiceRequired
  • Packing ListRequired
  • Bill of Lading / Airway BillRequired
  • CBP Entry Summary (7501)Required

    Prepared and filed by your customs broker

  • CBP Entry / Release (3461)Required

    Prepared and filed by your customs broker

  • Customs Bond (CBP 301)Conditional

    Required for formal entries — generally shipments valued over $2,500

    Single-entry or continuous bond, obtained through your broker or a surety

  • Importer Security Filing (ISF "10+2")Conditional

    Required for ocean freight only

    Filed electronically at least 24 hours before loading at the foreign port

  • Importer ID Input Record (CBP 5106)Conditional

    Required to establish or update your importer-of-record number with CBP

    One-time setup for a new importer; not filed per shipment

  • Entry Manifest (CBP 7533)Conditional

    Alternative to the 3461 for informal, low-value, or contiguous-country entries

Common questions

What is HTS code 3913?
HTS heading 3913 covers 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. It sits in Chapter 39 (plastics) of the US Harmonized Tariff Schedule and contains 5 tariff lines.
What is the duty rate for HTS 3913?
General duty rates from 4.2% to 6.5%, with 1 duty-free line. The general rate applies to most-favoured-nation trading partners; goods from countries with a free trade agreement may qualify for a reduced or duty-free special rate.
How many digits does a full HTS code have?
US import entries require the full 10-digit HTS code. Heading 3913 is the first four digits — the remaining six narrow it down to the specific product, which is what determines the duty rate you actually pay.

Related headings in Chapter 39