Disclosed is an Environmentally Limited Viability System for microorganisms based on differences between permissive and non-permissive environments. Leaked material is detected by one or more sensors in the containment space and, depending on the concentration or time rate of change in concentration of the leaked material, alarms and corresponding mitigation measures are reversibly activated to remove leaked material from the containment space. The invention also relates to a method of treating or preventing a bacterial infection, the method comprising administering to a patient a composition comprising the extract.