Chlorobutyl Rubber (CIIR) from Japan
Chlorinated isobutylene-isoprene rubber (CIIR) in primary pellet or bale form, where chlorinated monomer units predominate >95% by weight. Widely used in tire inner liners and pharmaceutical stoppers for air impermeability. Classified in 3911.90.70.00 as chlorinated synthetic rubber.
Duty Rate — Japan → United States
12.5%
Rate breakdown
9903.05.4912.5%Section 301 (forced labor) — Japan (col1 rate < 12.5 percent): MFN < 12.5% → total duty capped at 12.5%
Import Tips
• Include monomer weight breakdown certificate to satisfy note (a)(1) 'poly' designation rules
• Label as 'primary form' explicitly; compounded versions risk moving to 3926.90
• Avoid misdeclaration as regular butyl (4002.31); chlorination shifts to Chapter 39