With the issuance of this final order, the Administrator of the Drug Enforcement Administration will maintain the placement of the substance acetyl fentanyl (N-(1-phenethylpiperidin-4-yl)-N-phenylacetamide), including its isomers, esters, ethers, salts, and salts of isomers, esters and ethers, in schedule I of the Controlled Substances Act. This scheduling action is pursuant to the Controlled Substances Act and is required in order for the United States to discharge its obligations under the Single Convention on Narcotic Drugs, 1961. This action continues to impose the regulatory controls and administrative, civil, and criminal sanctions applicable to schedule I controlled substances on persons who handle (manufacture, distribute, import, export, engage in research or conduct instructional activities with, or possess), or propose to handle, acetyl fentanyl.