Kernite Sodium Borate Concentrate from Mexico
Kernite is a natural sodium borate (Na2B4O7·4H2O) concentrate from evaporated lake beds, used in welding fluxes and herbicides. HTS 2528.00.0050 covers this non-brine natural borate with H3BO3 content below 85% dry weight. Typically exported as crushed or powdered ore.
Duty Rate — Mexico → United States
10%
Rate breakdown
9903.03.0110%Except for products described in headings 9903.03.02–9903.03.11, articles the product of any country, as provided for in subdivision (aa) of U.S. note 2 to this subchapter
Import Tips
• Submit mining provenance docs proving non-brine extraction; test for hydration levels affecting weight basis
• Beware of rehydration during ocean transit impacting declared purity