The technology of using separating environments, whether protecting the world from a product or the product from the world. Containment, barrier isolation and isolation all refer to the same technology, which is enclosing an environment. In the interest of clarifying the existing confusion between the terms “isolators” and “barriers”, and providing authoritative implementation and validation of isolation technology, the Parenteral Drug Association (PDA) published in October 2000 the Draft for Technical Report No. 34 “Design and Validation of Isolator Systems for the Manufacturing and Testing of Health Care Products”. There are, however, some redefining terms that are gaining favor:1.Containment – protect the world from the product (as in the case of highly potent compounds or a toxic).2.Isolation – protect the product from the world (as in the case of a sterile product).3.ISO 14644-7 “Minienvironments and Isolators” will define further levels of devices.NOTE: Isolators, whether operated in a closed or open manner, offer significant advantages over barrier systems: isolators can be decontaminated using reproducible and validated methods, isolators do not allow the ingress of airborne contamination from the surrounding environment, and the introduction of personnel borne contamination into the isolator is precluded. In contrast, a barrier system is an open system that can exchange unfiltered air with the surrounding environment, can only be manually disinfected, and is directly accessed by gowned personnel.