Research project interference factors: Movement in the laboratory

Dynamic interference and its impact

Research for a safer laboratory:

Safety cabinets (SCs) are an important protective device in many biotechnological and pharmaceutical laboratories for the safe handling of hazardous substances or dangerous biological agents. The protective functions they provide are based on directional, balanced ventilation flows in the protected work area. They ensure that particulate releases do not reach the user (personal protection) and airborne contaminants are kept away from sensitive materials (product and carry-over protection).

These protective functions are tested in accordance with the currently valid standards using a microbiological test method - but in an empty laboratory. Influences by staff working in the laboratory are not taken into account in the tests. However, people unintentionally generate air movements with every movement and thus easily become a "disturbance factor" for the safe operation of a SC. As part of a research project lasting several years, Berner International has tested and quantified the influence of user activities on the protective functions.

In order to check the effects of user-induced airflow disturbances, the normatively required performance of various SWBs was first tested at the operating point specified by the manufacturer. By gradually reducing the SCs own protective airflows, it was then possible to evaluate the performance limits of the units in the presence and absence of person-induced disturbances. Depending on the model, this revealed very different safety reserves to compensate for the disturbances caused by the user. It could be shown quantitatively that dynamic disturbances in particular can have a considerable influence on the protective functions.