Moldy workplace?

Question Details: I work in a building in childcare and they found black mold on the drywall- this is not the first time. We closed down for several weeks and they replaced the drywall. They put a Ozone machine in the rooms saying that it would kill the mold.I have a feeling that mold is all over this place( vents ,floors ,etc) even though they says its OK (they are shady) Is it safe to go back in there and clean? What should we clean toys, and other things with?