HTS code 9902.10.40 covers "Mixture of precipitated silica gel (CAS No. 112926-00-8) and (4-hydroxy-2,2,6,6-tetramethyl-1-piperidinyl)oxidanyl (CAS No. 2226-96-2) of a kind used as polymerization inhibitors (provided for in subheading 3815.90.50)" under the US Harmonized Tariff Schedule. This is the official duty rate charged by US Customs when this product is imported into the United States, sourced directly from the U.S. International Trade Commission and refreshed daily.