4-Methylumbelliferone (CAS 90-33-5) from Mexico

4-Methylumbelliferone (4-MU) is a methylcoumarin derivative classified in HTS 2932.20.0500 for its coumarin lactone structure. Widely used as a fluorogenic substrate in biochemical assays and as a laser dye.

Duty Rate — Mexico → United States

16.5%

Rate breakdown

9903.03.0110%Except for products described in headings 9903.03.02–9903.03.11, articles the product of any country, as provided for in subdivision (aa) of U.S. note 2 to this subchapter

Import Tips

Provide fluorescence emission spectra data to confirm identity for lab/research imports

Declare if crystalline powder or solution form; pure compound stays in 2932

Include end-use statements for research chemicals to avoid pharmaceutical scrutiny