While you working you should wear safety cloth and wear goggles to protect your eyes.
While cutting any equipment be aware of it and don’t carry open knives around.
Use of paint & glue/solvents - use water based liquids, clean up spills.
Using suitable materials - check out fire ret ardency rules for particular venue
While you working in a group do not lift any heavy thing, and bend knees not you beck, you might damage it.
You have to make sure that the plant has to be big enough and not too hot.
Stage blackout, tripping/falling/colliding - Use of torches, all scenery positions clearly marked on the floor, rehears moves
Height hazard, falling off stage – Clear announcements to cast/crew, pulling curtain during blackouts
Props being lost/misused – Keep everything under controlled of prop manager.
Moving scenery – All crew have specific, well rehearsed job roles
Crowd control – You have to be make sure that the venue should not be over crowded, also the staff has to be by the door for the safety.
Fire – Clear announcements, signs, usual fire precautions.