The Joint Commission received two reports of medical gas mix-ups in 2000 that resulted in the death of four patients and injury to five patients. In the past four years, the Food and Drug Administration (FDA) has received four reports that resulted in seven deaths and 15 injuries. In early April 2001, the FDA issued a Guidance for Hospitals, Nursing Homes, and other Health Care Facilities--Public Health Alert (1) that focuses on its reports of medical gas mix-ups, their common causes and the FDA's recommendations for preventing occurrences. This Alert is being distributed to help spread the word to health care organizations about steps that can be taken to prevent deaths and injuries from compressed gases, which include industrial and medical grade gases. Medical grade gases are considered prescription drugs and include oxygen, compressed air, carbon dioxide, helium, nitrogen and nitrous oxide. These medical gases are either used in medical treatment and procedures, or to power medical equipment. Industrial grade gases should never be used medically. Medical gases come in many different types of vessels, but three of the FDA's four cases involved cryogenic vessels and their connectors, so this alert will focus on the problems associated with those vessels.