Dibutyltin Oxide Silicone Crosslinker from Mexico
Dibutyltin oxide serving as heat-activated crosslinker in RTV silicone sealants and adhesives. Classified in HTS 2931.90.90.21 as pure organo-tin compound, distinct from formulated sealant products. Direct tin-carbon bonds qualify it as organo-inorganic per Chapter 29 heading 2931 definition.
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
• Provide reaction mechanism documentation showing catalytic function to distinguish from polymer additives
• Ensure <0.1% heavy metal contaminants to meet silicone industry specifications and avoid 3824 classification
• Declare exact particle size distribution; nano-grade may trigger additional nanomaterial reporting