A drug free workplace is an employment setting where all employees adhere to a program of policies and activities designed to provide a safe workplace, discourage alcohol and drug abuse and encourage treatment, recovery and the return to work of those employees with such abuse problems. The intent of the program is to educate adults on the problems relating to substance abuse. The one place where there can be mandated adult education is the workplace. This empowers the individual and the family, resulting in stronger communities.
via The Council on Alcohol and Drugs: Drug Free Workplace FAQ.