Dye Coupling Grade Naphthalenetrisulfonic Acid Isomer Mix
Specialty isomer mixture (1,3,6- and 1,3,7-naphthalenetrisulfonic acids) optimized for diazo coupling in azo pigment production. HTS 2904.10.15.00 applies as chemically defined sulfonated naphthalene derivative per Chapter 29 exclusions from dyes.
Import Duty Rates by Country of Origin
Alternative Classifications
This product could be classified differently depending on its characteristics or intended use.
If contains both sulfo and carboxy groups (e.g., H-acid derivatives)
Derivatives with multiple functional groups classified by heading occurring last in numerical order.
If imported as disodium salt form
Sodium sulfonic acid salts may fall to inorganic sulfonic acids if not classified with organic parent.
If when supplied with stabilizers exceeding Chapter 29 note (f) allowances
Excess additives render it a chemical preparation rather than pure compound.
Not sure which classification is right?
The Tariff Assistant works through the GRI rules on your specific product to reach the right HTS code — and can price the duty on it in the same conversation.
Import Tips & Compliance
• Request supplier Certificate of Analysis specifying <0.5% impurities to maintain Chapter 29 chemical compound status
• Avoid retail packaging; bulk industrial shipments prevent shift to Chapter 32 retail dye provisions
• Check REACH compliance documentation for EU-origin material destined for US transshipment
Related Products under HTS 2904.10.15.00
Naphthyltrisulfonic Acid Mixture (1,3,6 & 1,3,7 Isomers)
This is a specific mixture of 1,3,6-naphthalenetrisulfonic acid and 1,3,7-naphthalenetrisulfonic acid isomers, classified under HTS 2904.10.15.00 as sulfonated derivatives of hydrocarbons containing only sulfo groups. It serves as a key intermediate in azo dye manufacturing, meeting Chapter 29 note (a) for separate chemically defined organic compounds.
1,3,6-1,3,7-NTS Acid for Acid Dyes
Mixture of naphthalenetrisulfonic acid isomers (1,3,6 & 1,3,7) used as diazo component in acid dye synthesis. Precisely matches HTS 2904.10.15.00 for mixtures of these specific sulfonated derivatives containing only sulfo groups.
1,3,6/1,3,7-Naphthalenetrisulfonic Acid Technical Grade
Technical grade mixture of 1,3,6- and 1,3,7-naphthalenetrisulfonic acid used in industrial dye synthesis. Falls under HTS 2904.10.15.00 per Chapter 29 scope for sulfonated hydrocarbon derivatives with only sulfo groups, excluding coloring matters of Chapter 32.
Industrial Naphthalene-1,3,6,7-Trisulfonic Acid Blend
Industrial-grade 50/50 blend of 1,3,6- and 1,3,7-naphthalenetrisulfonic acids for synthetic dye production. Classifies under HTS 2904.10.15.00 as the explicitly named mixture of these sulfonated hydrocarbon derivatives.