The restricted-access barrier system (RABS) can be an alternative to isolators and clean rooms. The RABS concept entails a physical barrier between operators and production areas, but the barrier is limited.
The level of contamination control lies somewhere on the spectrum between a conventional clean room aseptic process and an isolator process. A limited barrier is acceptable because RABS always must be set up in high-class clean rooms (at least ISO 7).
RABS provide product protection and contamination control by a combination of a ‘physical and aerodynamic barrier’ over the critical process zone. RABS offer the advantage of easier access to the process in the event that an intervention is required.
The extent of separation of the process and the surrounding environment, including the most potentially contaminating sources, people, set a scale of product protection and risk reduction of contamination during processing and in process transfers.
Bioquell have led the development in closed design RABS decontamination with a gaseous vapour phase process. Gassed RABS mitigate risk from aseptic assembly of out-of-place sterilised parts using a gassing-in-place (GIP) process for surface sterilisation of in-direct product contact parts e.g. feeder bowls. Optimised management of the condensable hydrogen peroxide vapour by maintaining the necessary 2-6 micron sub-visible micro-condensate yields optimium cycle times. For example a 30m3 filling line with a closed design RABS was validated with a 3 hour cycle time.
Open Design RABS which cannot be closed for Gaseous Vapour phase decontamination can use one of Bioquell's room decontamination systems so both RABS and cleanroom can be decontaminated together. An example from one project demonstrated a 4 hour validated cycle for the filling room, open RABS filling line with freeze dryer (Lyo) loading section (with pass through) to capper room. RABS barrier doors remained closed in the combined cycle with 6-log sporicidal efficacy achieved in the cleanroom and RABS barrier so indirect contact parts were also gassed-in-place and surface sterilised.