Performance of open-fronted microbiological safety cabinets: the value of operator protection tests during routine servicing

Validation of cross-contamination control in biological safety cabinet for biotech/pharmaceutical manufacturing process

For class II, type A2 biological safety cabinets (BSC), NSF/ANSI Standard 49 should be conformed in cabinet airflow velocity derivation, particle contamination, and aerodynamic flow properties. However, there exists a potential problem. It has been built that the cabinet air flow stabilize is influenced by the quantity of downflow of air and the height above the cabinet exhaust opening. Three air downflow quantities were compared as an operating apparatus was placed from 20 to 40 cm above the bench of the cabinet. The results show that the BSC air downflow velocity is a function of increased sampling height, displaying that containment is improvingly permitted over product protection as the sampling height decreases. This study investigated the concentration gradient of particles at various heights and downflow air quantity from the bench of the BSC. Experiment results indicate that performance near the bench was better than in the rest of the BSC. In terms of height, the best cleanliness was measured at a height of 10 cm over the bench; it reduced actually with add in height. The empirical curves accommodate, founded on the concentration gradient of particle created was elaborated for evaluating the particle concentration at different heights and downflow air quantity from the source of the bench of the BSC. The particle image velocimetry system applied for BSC airflow research to fix amount of airflow patterns and air distribution measurement and results of measurements show how obstructions can greatly influence the airflow and contaminant transportation in a BSC.

Evidence-based biosafety: a review of the principles and effectiveness of microbiological containment measures

We examined the available evidence on the effectiveness of measures aimed at protecting humans and the environment against the risks of working with genetically modified microorganisms (GMOs) and with non-GMO pathogenic microorganisms. A few principles and methods underlie the current biosafety practice: risk assessment, biological containment, concentration and enclosure, exposure minimization, physical containment, and hazard minimization. Many of the current practices are based on experience and expert judgment. The effectiveness of biosafety measures may be evaluated at the level of single containment equipment items and procedures, at the level of the laboratory as a whole, or at the clinical-epidemiological level. Data on the containment effectiveness of equipment and laboratories are scarce and fragmented. Laboratory-acquired infections (LAIs) are therefore important for evaluating the effectiveness of biosafety. For the majority of LAIs there appears to be no direct cause, suggesting that failures of biosafety were not noticed or that containment may have been insufficient. The number of reported laboratory accidents associated with GMOs is substantially lower than that of those associated with non-GMOs. It is unknown to what extent specific measures contribute to the overall level of biosafety. We therefore recommend that the evidence base of biosafety practice be strengthened.