8-Amino-1-naphthol-5-sulfonic acid (Schaeffer's acid) from Mexico
Schaeffer's acid is explicitly named in HTS 2922.21.1000 and functions as a dye intermediate for acid wool dyes and reactive dyes. Its sulfonic acid group enhances water solubility while maintaining coupling reactivity. Commonly imported at 96% minimum assay.
Duty Rate — Mexico → United States
15.8%
Rate breakdown
9903.05.5510%Except for products described in headings 9903.05.85–9903.05.92 and 9903.05.94, articles the product of Mexico, as provided for in U.S. note 52 to this subchapter
Import Tips
• Isomer-specific NMR spectrum confirms identity versus gamma acid or other isomers
• Anti-caking agent declaration required if >1% added (permitted by chapter note 1(f))
• Temperature-controlled shipping prevents degradation above 40°C