Toluidine Blue O (Basic Blue 17)
Toluidine Blue O is a thiazine dye derived from toluidine, used in histology and microbiology staining. While primarily a colorant, its toluidine base and chemical purity qualify it under HTS 2921.43.90 rather than Chapter 32 when imported as pure compound. Pharmaceutical grade requires >85% purity.
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More Specific Codes
This product may fall under a more specific subheading:
Alternative Classifications
This product could be classified differently depending on its characteristics or intended use.
If synthetic acid dye preparation
Dyes put up commercially for end-use classify in Chapter 32 regardless of chemical origin.
If diagnostic reagent formulation
Ready-to-use staining solutions classify as diagnostic reagents.
If primarily heterocyclic structure
Thiazine core may dominate classification if amine function subordinate.
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Import Tips & Compliance
• Provide dye index number (C.I. 52040) and absorption spectrum for identity confirmation
• Pharma grade requires USP/NF certificate; technical grade may face 3204 scrutiny
• Declare metachromatic staining end-use to support Chapter 29 classification
Related Products under HTS 2921.43.90
p-Toluidine
p-Toluidine, also known as 4-methylaniline, is an aromatic monoamine derivative with the chemical formula C7H9N. It falls under HTS 2921.43.90 as a toluidine (methyl-substituted aniline) that is not specifically listed elsewhere in the subheading for toluidines and their salts. Commonly used in dye synthesis and as a chemical intermediate.
o-Toluidine Hydrochloride
o-Toluidine hydrochloride is the salt form of 2-methylaniline, a toluidine derivative used in pharmaceutical synthesis. Classified under HTS 2921.43.90 per Chapter Note (C)(1) as the salt retains classification of the parent aromatic monoamine. The hydrochloride improves handling and solubility for industrial applications.
m-Toluidine (3-Methylaniline)
m-Toluidine, or 3-methylaniline, is a meta-substituted toluidine used as an intermediate in agrochemical production. It qualifies under HTS 2921.43.90 as an 'other' toluidine derivative not covered by more specific subheadings. The methyl group distinguishes it from aniline (2921.42).
N-Ethyl-o-Toluidine
N-Ethyl-o-toluidine is an N-alkylated derivative of o-toluidine used in rubber accelerator production. It remains classified under HTS 2921.43.90 as a toluidine derivative; N-substitution doesn't change the principal aromatic monoamine characteristic. Purity >98% ensures Chapter 29 applicability.
4-Chloro-o-Toluidine
4-Chloro-o-toluidine is a halogenated toluidine derivative used in azo pigment synthesis. Classified in HTS 2921.43.90 as Chapter Notes confirm halogenated derivatives remain with parent amine classification. The dual substitution maintains toluidine identity.
Acetyl-p-Toluidine
Acetyl-p-toluidine (N-(4-methylphenyl)acetamide) is an acetylated toluidine used as a dye intermediate and analgesic precursor. The principal amine-function characteristic governs classification under HTS 2921.43.90 despite acetylation; oxygen-function subordinate per Chapter Notes.