Fluorosilicic Acid (Hexafluorosilicic Acid) from Mexico
Fluorosilicic acid (H2SiF6) is produced from phosphate processing, used in water fluoridation. Although fluorosilicates have provisions, concentrated forms fall under HTS 2826.90.90.90 as other complex salts when not specifically provided for. Chemically defined per subheading note.
Duty Rate — Mexico → United States
3.1%
Rate breakdown
9903.05.860%Articles provided for in subdivision (b) of U.S. note 52 to this subchapter
Import Tips
• Declare SiF6 content precisely (20-30%); transport as UN 1778; obtain water treatment end-use certification to avoid chemical weapon concerns