1-Naphthylamine-4,8-disulfonic Acid (Casella's Acid) from Japan
Casella's acid features dual sulfonic groups on the 1-naphthylamine backbone, used in direct dyes. While not explicitly named, its structural similarity to listed 2921.45.25.00 compounds and retention of primary amine function justifies inclusion. Chapter 29's last-in-order rule prioritizes amine over sulfonated classifications.
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
• Document sulfonic group count and positions via MS/NMR for classification support
• Use low-temperature storage (<25°C) and declare stability data
• Separate from mono-sulfonic isomers to avoid mixture designation confusion