Containment testing

We carry out containment testing to BS EN 14175, including robustness testing.

 

CSW Objectives. To establish the containment performance of the system to enable direct comparison between systems and, in cases where more than one system is available, to allow fume cupboards to be more effectively matched with the hazards associated with specific hazardous substances and experiments. The cupboard can be tested either empty or inclusive of normal operating apparatus, the latter being more representative of operating conditions.

 

CSW Method of testing. A gaseous challenge of sulphur hexafluoride (SF6) in nitrogen is injected into the enclosure at a precisely controlled rate to simulate the release of a contaminant within the cupboard. An array of sampling heads is positioned at the enclosure aperture and allowed to collect any SF6 which is able to migrate across the boundary. Leakage is detected by means of an infra-red gas analyzer, connected to a PC which allows real-time display of the data as a trace of leakage (ppm) against time. The measurement is repeated with the array in six/eight positions across the aperture.

 

Results. Containment performance is expressed as leakage of SF6 in parts per million (ppm), both as a mean and an instantaneous maximum value. The values awarded to each cupboard are those corresponding to the worst of the six array positions. These values are then applied to the classification categories, which includes guidance on the limitations of use for the system in the light of its performance.