A restricted access barrier system (Rabs isolator) provides for the aseptic packaging of milk and drinks. The isolator, the SAS 3 from Serac Inc, Carol Stream, Ill, (serac-group.com), increases productivity by working up to 72 hours without intermediate decontamination and by filling 50,000 bottles/hr. According to Serac, Rabs has unidirectional flow, barrier zones, and easy access, unlike standard isolators.

Unidirectional flow refers to several air barriers. Most isolators use hermetic seals. Rabs, on the other hand, uses barriers of positive air pressure inside the enclosure to protect the sterile area. Air continuously circulates and is renewed by a vertical unidirectional air control. This eliminates particles in the enclosure and protects against contamination.

The sterile area is surrounded by barrier zones also subject to unidirectional airflow. The company says the additional protective envelope between the enclosure and rest of the workshop simplifies cleaning and maintenance.

The sterile enclosure is accessible during production only through glove boxes at critical locations along the line. Operators reach all other points, such as the treatment, input, and output lines, through external doors without having to wear cleanroom clothing. All accesses into and out of the barrier zone are monitored and recorded to track operations.