Toluidine Blue O (Basic Blue 17) from Canada
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.
Duty Rate — Canada → United States
16.5%
Rate breakdown
9903.05.2910%Except for products described in headings 9903.05.85–9903.05.93, articles the product of Canada, as provided for in U.S. note 52 to this subchapter
Import Tips
• 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