4-Sulfo-1,8-Naphthalic Anhydride
4-Sulfo-1,8-naphthalic anhydride is a sulfonated aromatic polycarboxylic anhydride used in fluorescent brighteners and dye intermediates. Explicitly listed in HTS 2917.39.04.00 covering sulfonated derivatives per Chapter notes. Chemically defined compound with sulfo group directly characterized.
Import Duty Rates by Country of Origin
Alternative Classifications
This product could be classified differently depending on its characteristics or intended use.
If used directly as fluorescent brightening agent
Chapter 29 exclusion (g) directs finished fluorescent agents to heading 3204.
If primary classification as organo-sulfur compound
Sulfur directly linked to carbon could trigger heading 2930 per Chapter notes if not principally carboxylic.
If other unsulfonated naphthalic anhydrides
Desulfonated analog falls under general aromatic anhydride provisions.
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Import Tips & Compliance
• Verify CAS 81-46-9 registration; confirm sulfo group content via FTIR spectroscopy
• Hazard Class 8 corrosive labeling required (UN 3261); segregation from amines mandatory
• Dye industry end-use certificates prevent reclassification as coloring matter (Chapter 32 exclusion)
Related Products under HTS 2917.39.04.00
Phthalic Anhydride Flakes
Phthalic anhydride in flake form is a key aromatic polycarboxylic anhydride used primarily in the production of plasticizers for PVC and polyester resins. It falls under HTS 2917.39.04.00 as it is specifically listed as 'Phthalic acid' (understood to include its anhydride form per tariff convention). This chemically defined organic compound meets Chapter 29 note (a) for separate compounds.
Trimellitic Anhydride Powder
Trimellitic anhydride (1,2,4-benzenetricarboxylic acid 1,2-anhydride) powder is used in wire enamels, polyester resins, and plasticizers. Explicitly listed under HTS 2917.39.04.00 as a separate chemically defined aromatic polycarboxylic anhydride per Chapter 29 scope. Meets criteria for pure organic compounds without excluded additives.
Phthalic Acid Crystals
Phthalic acid (1,2-benzenedicarboxylic acid) in crystalline form serves as an intermediate for phthalic anhydride production and direct use in resins. Specifically enumerated under HTS 2917.39.04.00 as an aromatic polycarboxylic acid. Qualifies as chemically defined compound per Chapter 29 note (a).
Phthalic Anhydride 99.8% Pure Technical Grade
High-purity technical grade phthalic anhydride (99.8% min) for phthalate ester production in coatings and adhesives. Specifically covered under HTS 2917.39.04.00 listing with trace maleic anhydride impurity allowed per industry standards. Meets 'separate chemically defined' criteria.
Industrial Phthalic Anhydride Molten
Molten phthalic anhydride delivered in heated tankers for direct pipeline feed to alkyd resin plants. Remains classified under HTS 2917.39.04.00 as the pure chemical compound in transport form. Physical state does not affect chemical classification per tariff conventions.