The Deputy Administrator of the Drug Enforcement Administration (DEA) is issuing this final order to temporarily schedule 10 synthetic cathinones into schedule I pursuant to the temporary scheduling provisions of the Controlled Substances Act (CSA). The 10 substances are: 4-methyl-N-ethylcathinone (``4-MEC''); 4-methyl-alpha-pyrrolidinopropiophenone (``4-MePPP''); alpha-pyrrolidinopentiophenone (``[alpha]-PVP''); 1-(1,3-benzodioxol-5-yl)-2-(methylamino)butan-1-one (``butylone''); 2-(methylamino)-1-phenylpentan-1-one (``pentedrone''); 1-(1,3-benzodioxol-5-yl)-2-(methylamino)pentan-1-one (``pentylone''); 4-fluoro-N-methylcathinone (``4-FMC''); 3-fluoro-N-methylcathinone (``3-FMC''); 1-(naphthalen-2-yl)-2-(pyrrolidin-1-yl)pentan-1-one (``naphyrone''); and alpha-pyrrolidinobutiophenone (``[alpha]-PBP''). This action is based on a finding by the Deputy Administrator that the placement of these synthetic cathinones and their optical, positional, and geometric isomers, salts and salts of isomers into schedule I of the CSA is necessary to avoid an imminent hazard to the public safety. As a result of this order, the regulatory controls and administrative, civil, and criminal sanctions applicable to schedule I controlled substances will be imposed on persons who handle (manufacture, distribute, import, export, engage in research, conduct instructional activities, and possess), or propose to handle these synthetic cathinones.