Neville-Winter Acid (1-Naphthylamine-5-sulfonic Acid) from China
Neville-Winter acid is an aminohydroxynaphthalenesulfonic acid used in acid dye manufacturing, subject to HTS 2922.21.4000 quotas under U.S. note 3 to section VI. Its structure with amino group ortho/para to sulfonic acid enables diazotization for azo coupling. Classification adheres to chapter priority for oxygen-function amino-naphthols.
Duty Rate — China → United States
24%
Rate breakdown
9903.03.0110%Except for products described in headings 9903.03.02–9903.03.11, articles the product of any country, as provided for in subdivision (aa) of U.S. note 2 to this subchapter
9903.88.157.5%Except as provided in headings 9903.88.39, 9903.88.42, 9903.88.44, 9903.88.47, 9903.88.49, 9903.88.51, 9903.88.53, 9903.88.55, 9903.88.57, 9903.88.65, 9903.88.66, 9903.88.67, 9903.88.68, or 9903.88.69, articles the product of China, as provided for in U.S. note 20(r) to this subchapter and as provided for in the subheadings enumerated in U.S. note 20(s)
Import Tips
• Use HTS statistical annotations to track quota consumption and avoid over-import penalties
• Label containers with full IUPAC name and CAS (84-86-6) for rapid customs verification
• Test for impurities that could disqualify 'chemically defined' status per chapter note (a)