Final answer:
The controlled substance logbook is mandated by the Controlled Substances Act (CSA), which is the legislation requiring the monitoring and logging of certain substances.
Step-by-step explanation:
The legal requirement for a controlled substance logbook is mandated in the Controlled Substances Act (CSA). The CSA was passed by Congress in 1970 to control the manufacture, importation, possession, use, and distribution of certain substances. It categorizes drugs into different schedules according to their potential for abuse and medicinal value. The FDA oversees the regulation of foods, drugs, and cosmetics under the Federal Food, Drug, and Cosmetic Act (FDCA), but the CSA is the specific act that requires the logging of controlled substances.