Boric Acid Trimethyl Ester from Mexico
Trimethyl borate, ester of boric acid and methanol, used as boron source in ceramics, flame retardants, and organic synthesis. HTS 2920.90.51.00 covers esters of boron inorganic acid (nonmetal). Volatile liquid intermediate.
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
• Hydrolyzes in air; import under nitrogen requires special packaging declaration
• Boron content assay confirms inorganic acid ester status