Things get a little messy sometimes in most industrial facilities. Or a lot messy.
Areas where sprays and aerosols are used aren’t friendly to the rest of the operation, but they also need to exist in the same facility. Perhaps thermal zones are needed where there was once plenty of space. Welding stations may be in areas more highly populated with other workers. Amongst all these considerations is also the fluidity of your operations as the company grows and changes. Are permanent solutions (walls) the right answer?