H Acid Free Acid (4-Amino-5-hydroxy-2,7-naphthalenedisulfonic acid)
The free acid form of H acid is specifically enumerated in HTS 2922.21.1000 alongside its salts. Less common than salt forms but used where specific pH control needed in dye coupling. Highly water-soluble despite free sulfonic groups.
Import Duty Rates by Country of Origin
Alternative Classifications
This product could be classified differently depending on its characteristics or intended use.
If for disulfonic acid without amino function consideration
Sulfonic acids lacking nitrogen functions classify earlier per numerical order rule
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Import Tips & Compliance
• Neutralization equivalence point titration confirms free acid content
• Stronger corrosivity requires UN 3265 class 8 designation
• Specialized ventilation for dust exposure during unloading
Related Products under HTS 2922.21.10.00
Chicago Acid (4-Amino-5-hydroxy-1,3-naphthalenedisulfonic acid)
Chicago Acid is a specific aminohydroxynaphthalenedisulfonic acid used primarily as an intermediate in the synthesis of reactive dyes and azo pigments. It falls under HTS 2922.21.1000 as one of the enumerated oxygen-function amino-naphthol sulfonic acids containing both amino and hydroxy groups with sulfonic acid functions. This chemically defined organic compound is supplied as a powder or solution for industrial dye production.
H Acid Monosodium Salt (4-Amino-5-hydroxy-2,7-naphthalenedisulfonic acid, monosodium salt)
H Acid monosodium salt is a key dye intermediate specifically enumerated under HTS 2922.21.1000 for use in manufacturing direct, reactive, and acid dyes. This salt form improves solubility and handling compared to the free acid. It contains both amino and hydroxy functions with naphthalene sulfonic acid structure as defined in chapter notes.
1-Amino-8-hydroxy-3,6-naphthalenedisulfonic acid
This specific diaminohydroxynaphthalenedisulfonic acid is explicitly listed in HTS 2922.21.1000 and serves as a diazo coupling component in acid dye synthesis. Its structure features both amino (-NH2) and hydroxy (-OH) oxygen functions on the naphthalene ring with sulfonic acid groups. Supplied as technical grade powder (95%+ purity) for chemical manufacturing.
6-Amino-1-naphthol-3-sulfonic acid (J Acid)
J Acid (6-Amino-1-naphthol-3-sulfonic acid) and its salts are specifically enumerated under HTS 2922.21.1000 as essential intermediates for direct and reactive dyes used in cellulosic fibers. The compound's ortho amino-hydroxy positioning enables stable azo coupling. Typically imported as 92-98% purity technical grade.
8-Amino-1-naphthol-5-sulfonic acid (Schaeffer's acid)
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.
H Acid Monopotassium Salt
The monopotassium salt of 4-Amino-5-hydroxy-2,7-naphthalenedisulfonic acid (H acid) is specifically listed in HTS 2922.21.1000. This salt form offers different solubility characteristics than sodium salt for specific dye applications. Classifies as organic salt of enumerated base per chapter note 3(C).