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
9903.05.5510%Section 301 (forced labor) — additional 10% ad valorem on products of Mexico
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