Dioxolane Monomer from Mexico
1,3-Dioxolane features a five-membered ring with two oxygen hetero-atoms, used as comonomer in polyacetal resin production and pharma intermediates. Pure monomer form qualifies as heterocyclic oxygen compound under HTS 2932.99.90.90. Excluded from cyclic ester provisions by Chapter note 5.
Duty Rate — Mexico → United States
110%
Rate breakdown
9903.04.6096.3%Except as provided in heading 9903.04.61, patented pharmaceutical articles as provided for in subdivisions (c) and (d) of U.S. note 40 to this subchapter
9903.05.5510%Except for products described in headings 9903.05.85–9903.05.92 and 9903.05.94, articles the product of Mexico, as provided for in U.S. note 52 to this subchapter
Import Tips
• Polymerization inhibitor content <50ppm required to maintain monomer classification
• Formaldehyde residual limits <0.1% prevent reclassification as formaldehyde derivative
• Glass-lined containers mandatory for moisture-sensitive dioxolane shipments