Cross-Linked Casein Derivative from Mexico
Cross-linked casein derivative features polymerized casein chains for biomedical coatings and slow-release fertilizers. It is covered by HTS 3501.90.60.00 as other derivatives, explicitly excluding hardened proteins of 3913. The cross-linking process defines its modified protein structure.
Duty Rate — Mexico → United States
10%
Rate breakdown
9903.05.5510%Except for products described in headings 9903.05.85–9903.05.92 and 9903.05.94, articles the product of Mexico, as provided for in U.S. note 52 to this subchapter
Import Tips
• Document cross-linking agent and degree of polymerization to exclude 3913 hardened proteins
• Obtain biotech end-use letters for dual commercial/research imports
• Use nitrogen solubility index tests (>70%) to affirm non-hardened status