Okay well... I'm going to move this where it makes more sense...
It is safe to ingest as long as you allowed as much time as needed for any pest treatments to break down. So if you used pyrethrin at any time, it should be 3 weeks. Other than that, puff away.
Before hypothetically growing again, bomb your grow area twice with pyrethrin or if there are no plants in there, a household bug bomb. Good luck.