HTS code 2909.49.05.00 covers "Ethers, ether-alcohols, ether-phenols, ether-alcohol- phenols, alcohol peroxides, ether peroxides, acetal and hemiacetal peroxides, ketone peroxides (whether or not chemically defined), and their halogenated, sulfonated, nitrated or nitrosated derivatives › Aromatic ethers and their halogenated, sulfonated, nitrated or nitrosated derivatives › Other › Guaifenesin" 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.