Unsaturated Polyester Resin (UPR) from China
Liquid unsaturated polyester resin for fiberglass composites in marine and construction applications, supplied in primary form before curing. It enters HTS 3907.99.5050 as 'other polyesters' per predominant dicarboxylic acid/diol monomer content per subheading note (a).
Duty Rate — China → United States
44%
Rate breakdown
9903.88.0225%Except as provided in headings 9903.88.12, 9903.88.17, 9903.88.20, 9903.88.54, 9903.88.59, 9903.88.61, 9903.88.63, 9903.88.66, 9903.88.67, 9903.88.68, 9903.88.69, or 9903.88.70, articles the product of China, as provided for in U.S. note 20(c) to this subchapter and as provided for in the subheadings enumerated in U.S. note 20(d)
9903.05.3112.5%Section 301 (forced labor) — additional 12.5% ad valorem on products of China
Import Tips
• Include Safety Data Sheets (SDS) detailing uncured resin status and monomer composition for primary form verification
• Avoid common pitfall of classifying styrene-monomer blends incorrectly; styrene <5% keeps it polyester-dominant
• Confirm not chemically modified beyond base polymer to stay out of generic 'Other' provisions