Safety cabinet – many people know it, but not everyone knows how to use it properly…

What is often forgotten: If they are used as a protective measure and therefore not exclusively for product protection, they are considered safety-relevant equipment. There are a few things to consider here. In principle, according to Annex 2 AI b. Paragraph 6 GenTSV (2019), even when working with organisms in risk group 1 that have sensitizing or toxic effects, a biological safety cabinet must be used if aerosol formation is to be expected. From risk group 2 onwards, all work where aerosol formation is possible must be carried out under the safety cabinet, as regulated in Annex 2 A. II. a. Paragraph 6 aa) GenTSV. But what exactly are safety cabinets? Before we look at this further, let's clarify the term aerosols: Aerosols are tiny droplets that, due to their small size, are carried through the air and can therefore be easily inhaled. They can be generated simply by the bursting of a liquid film, such as the bursting of a bubble. Another possibility is mixing samples with a vortexer or simply by spilling a sample. When reviewing the various work steps, you will find even more possibilities for generating aerosols, so these activities must be carried out under a safety cabinet.

Microbiological safety cabinets (MSW) are divided into three classes. The workbench with the least degree of protection is Class I. Here, employees are protected inside, but product protection is not provided. Employees can carry out their activities in the workbench through the work opening . The air flow is sucked in through the work opening, guided over the work surface and directed upwards through a filter so that no aerosols can escape. Since the air flow from the outside is directed directly over the work materials, product protection is not provided. Further information can also be found in the BG Chemie leaflet B 011. In the following newsletters, as part of a series, the individual classes and further information on microbiological safety cabinets will be discussed in more detail.