Diethylphosphinic Acid from Canada
Diethylphosphinic acid is an organophosphorus compound used as flame retardant in polymers. Classified in 2931.90.90.52 as organo-inorganic acid-function compound not covered by earlier P-specific headings.
Duty Rate — Canada → 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
• Corrosive solid UN 3261; use fiber drums with polyethylene liner
• Flame retardant claims require UL certification for end-use validation
• Distinguish from phosphonic acids (2929.90) via P-C vs P-OH bonding