Uncontrolled release of biological material from its containment. This either threatens to, or does, cause exposure to a biological hazard. Such an incident may occur accidentally or deliberately.

Provision of physical and biological barriers to the dissemination of potentially hazardous biologically active agents (bacteria, viruses, recombinant DNA, etc.). Physical containment involves the use of special equipment, facilities, and procedures to prevent the escape of the agent. Biological containment includes use of immune personnel and the selection of agents and hosts that will minimize the risk should the agent escape the containment facility.

Accidentally acquired infection in laboratory workers.