Crown Ether 18-Crown-6 from China
18-Crown-6 is a macrocyclic polyether with six oxygen hetero-atoms in 18-membered ring, used for phase transfer catalysis and metal ion complexation. Pure compound qualifies under 2932.99.90.90 as heterocyclic oxygen compound not specifically excluded. Chemically defined per Chapter 29 note 1(a).
Duty Rate — China → United States
16.2%
Rate breakdown
9903.05.3112.5%Section 301 (forced labor) — additional 12.5% ad valorem on products of China
Import Tips
• Molecular weight certification confirms macrocyclic structure vs linear polyethers
• Hygroscopic nature requires <20% RH storage declaration on shipping papers
• Complexing agent registration under TSCA required for first import