Risk of addiction through occupational exposure to drugs of abuse is an important but relatively neglected public health problem. Stress and access may have much less of a role in addiction among certain populations than originally was thought. Risk of addition may be increased dramatically by unintentional exposure in the workplace to potent substances that sensitize the brain. Everyone knows that second-hand inhalation of crack vapors is a very dangerous proposition, but rarely has alarm been raised about exposing anesthesiologists to second-hand fentanyl. Additional studies of the relationship between exposure in the workplace and addiction are necessary. These studies should include biological measures, such as blood levels in exposed workers, and sensitive assays that quantitatively assess levels of exposure in the workplace.