This rulemaking changes the regulation of the listed chemical iodine under the chemical regulatory provisions of the Controlled Substances Act (CSA). The Drug Enforcement Administration (DEA) believes that this action is necessary to remove deficiencies in the existing regulatory controls, which have been exploited by drug traffickers who divert iodine (in the form of iodine crystals and iodine tincture) for the illicit production of methamphetamine in clandestine drug laboratories. This rulemaking moves iodine from List II to List I; reduces the iodine threshold from 0.4 kilograms to zero kilograms; adds import and export regulatory controls; and controls chemical mixtures containing greater than 2.2 percent iodine. This rulemaking establishes regulatory controls that will apply to iodine crystals and iodine chemical mixtures that contain greater than 2.2 percent iodine. This regulation therefore controls iodine crystals and strong iodine tinctures/solutions (e.g., 7 percent iodine) that do not have common household uses and instead have limited application in livestock, horses, and for disinfection of equipment. Household products such as 2 percent iodine tincture/solution and household disinfectants containing iodine complexes will not be adversely impacted by this regulation. Additionally, the final rule exempts transactions of up to one-fluid-ounce (30 ml) of Lugol's Solution. Persons handling regulated iodine materials are required to register with DEA, are subject to the import/export notification requirements of the CSA, and are required to maintain records of all regulated transactions involving iodine regardless of size.