An IT-Ticket should hopefully resolve the problem with the Office-Version. But this can take some days

@Glenn: As long as all of you sacrifice your valuable time and support me, I can't get battle-weary! For me this support doesn't come naturally and I will provide data and help wherever I can.

To explain the formula:
There are two issues (one minor, one major):

Minor issue/blemish: I get #NV for some rooms that are not able to handle the chemical with the entered GHS-hazard-classes. If possible I would like to show just the rooms which are able to handle the according chemical. Unfortunately I can't tell you why this occurs. In total we have 10 rooms in the database and X(couldn't find the exact number)-13 rows shown (some with #NV) in the formula.

Major issue: Sometimes there is a different/wrong result compared to Hans'. When you for example choose "Organische Peroxide B" and "Brennbare Flüssigkeiten 1" room 6 should contain the texts for 1,4 and 5. Your formula just contains 4 and 5. The reason for this exceeds my Excel-knowledge as well

I will pause working for today and would come back here early tomorrow. If there is something unclear with my explanation I'll try to show it better in a samplebook. Thanks again for the help so far!