Tert-Butylphosphonic Acid from Mexico
Tert-butylphosphonic acid (t-BuP(O)(OH)2) contains direct P-C bond to tertiary butyl group. Classified HTS 2931.49.0080 as non-halogenated organo-phosphorus derivative. Used in metal surface treatment and polymer additives.
Duty Rate — Mexico → United States
100%
Rate breakdown
9903.04.6096.3%Pharmaceuticals Annex IV: patented pharma articles — 100% floor rate
9903.05.900%Articles already subject to Section 232 (steel/aluminum/copper + derivatives, autos + parts, wood, medium/heavy vehicles + parts, semiconductors, patented pharma) — U.S. note 52(f)
Import Tips
• pH stability data required for aqueous solutions
• Corrosive solid UN 3261; proper inner packaging essential
• Avoid classification as mixture if >90% purity