Single Yarn of Polyester Staple Fibers, ≥85% by Weight, Not for Retail Sale

Polyester staple single yarn classified under 5509210000 and originating from China is subject to Section 301 tariffs, which add to the standard MFN duty. This has prompted some importers to diversify sourcing to other Asian producers not subject to Section 301 measures. However, origin must be determined under US rules of origin — substantial transformation rules apply, and yarn processed through multiple countries requires careful origin analysis.

A manufacturer's fiber composition certificate or test report from an accredited laboratory is the standard documentation. CBP may request lab testing if the fiber content is disputed. For blended yarns near the 85% threshold, even small variations in composition can shift classification to a different subheading, so importers should build tolerance checks into supplier quality agreements.