All personnel performing any research activity with controlled substances must sign the Authorized Users Signature Log. The log is one of the documents required by University policy that must be kept up-to-date and filed in the research controlled substances records. The Authorized User Signature Log, like all controlled substance records, must be kept for a minimum of three years. When someone leaves the laboratory, note the date the person departed on the log. If there is high turnover in the lab, a new log may need to be started. Originals of all Authorized User Signature Logs must be kept with the controlled substance records.