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Polyglycol Ester of Methylphosphonic Acid Flame Retardant from China

This is a specific polyglycol ester of methylphosphonic acid used as a flame retardant additive in polyurethane foams and plastics. It falls under HTS 3824.92.00.00 because it is explicitly classified as polyglycol esters of methylphosphonic acid, a chemical preparation not elsewhere specified. These compounds provide fire resistance by releasing non-flammable gases when exposed to heat.

Duty Rate — China → United States

42.5%

Rate breakdown

9903.88.0325%Except as provided in headings 9903.88.13, 9903.88.18, 9903.88.33, 9903.88.34, 9903.88.35, 9903.88.36, 9903.88.37, 9903.88.38, 9903.88.40, 9903.88.41, 9903.88.43, 9903.88.45, 9903.88.46, 9903.88.48, 9903.88.56, 9903.88.64, 9903.88.66, 9903.88.67, 9903.88.68, or 9903.88.69, articles the product of China, as provided for in U.S. note 20(e) to this subchapter and as provided for in the subheadings enumerated in U.S. note 20(f)
9903.05.3112.5%Section 301 (forced labor) — additional 12.5% ad valorem on products of China

Import Tips

Verify chemical composition via lab analysis to confirm it meets the exact definition of polyglycol esters of methylphosphonic acid

Include Safety Data Sheets (SDS) and TSCA certification for US EPA compliance, as these are regulated flame retardants

Avoid misclassification as generic plastic additives under 3824.99; specify phosphonate structure in invoices