ABSTRACT
When unidirectional air flow benches/units are used for processes sensitive to contamination, a thorough function check with equipment in place should always be carried out during the Installation Qualification. In order to reduce the influence of unfavorable stagnation regions and vortex structures with the risk for accumulation of contaminants, visualization tests should be carried out when designing the side walls. The systematic approach with Visualization of Air Movements, Particle Challenge Tests, and calculation of the Risk Factor presents a method—the LR-Method—to evaluate the risks of human interference in a critical zone, such as aseptic filling line. The LR-Method is an engineering tool that provides valuable information concerning weak links. The tracer gas method can be used to evaluate and compare the containment performance of ventilated work stations without recirculation of air. The method also gives information regarding operator safety and the importance of good working performance and discipline.
