Not sure about Indonesian food safety regulations, but in Canada there's no limits for Y&M in production/packaging facilities. Every company establishes their own limits depending on products they produce, environment, HVAC/air making system, etc. I was told by the lab scientist that limit we established (less than 100 cfu/plate) is extremely low as it could be thousands, and it's normal number. For instance, if you have plants in your facility it could contribute in a higher number of yeast in air, wet environment is also adding number of mold cfu, etc. Through all these years of my experience working in different industries, I've never been told either by government inspectors or auditors what Y&M limits should be for the production air.