Toluidine Blue O from Canada
Toluidine Blue O (C15H16ClN3S) is a thiazine dye derived from toluidine, but as a chemically defined compound primarily used as biological stain, classified under HTS 2921.43.90.90. Not excluded as retail coloring matter.
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
• Include CAS 92-31-9 and dye index CI 52040; prove not 'put up for retail sale' per Chapter Note 2(g)
• Lab chemical imports require end-user certificates to prevent diversion to textile use
• Verify no metal coordination that shifts to later Chapter 29 coordination compounds