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, other

HTS 3913.90 is a 6-digit subheading of the U.S. Harmonized Tariff Schedule covering 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. It belongs to Chapter 39 and rolls up 4 10-digit statistical lines that brokers actually file at entry.

General (Column 1) duty rates for the 10-digit lines under HTS 3913.90 range from Free to 6.5%. The exact rate depends on the specific 10-digit statistical line — pick a line below to see its full rate detail.

U.S. Customs requires entries to be filed at the 10-digit statistical level — the broader subheading HTS 3913.90 is not directly fileable. Match your product description to the most specific 10-digit line in the list on this page; if multiple lines could apply, the General Rules of Interpretation (GRIs) and chapter notes determine which one governs.

No active AD/CVD (antidumping or countervailing duty) orders currently flag any line under HTS 3913.90 in Tandom's catalog. Tandom monitors Federal Register notices daily; any new orders will appear here within 24h of publication.