Have knowledge of hazard symbols and signs (for example: toxic, flammable, irritant, electrical danger, slippery surface)
Have knowledge of safety equipment (for example: goggles, gloves, masks, ear defenders).
Have knowledge of how and where to turn off main supplies (water, electricity, gas) to the house. Know how to isolate individual electrical circuits at the consumer unit.
I always run things as bases (i find it easier)
"Have knowledge of hazard symbols and signs"
See attachment (Safety First+Safety Symbols). Draw on a white board or show them pictures of the main different hazard symbols and signs. Bring some examples down of ones they are likely to see or use. Meths, Parafin (if you use those types of cookers) bleach etc. If you have time show them some others like constructions site ones.
"Have knowledge of safety equipment"
Bring some basic PPE down, goggles, gloves, mask, ear defenders. Explain how to use them correctly and why you would use them. If you have access to more, it can be a good chance to cover different types of PPE. Maybe even get the group to dress up one person in as much as they can. (Boiler suit, Steel Toe-capped Boots, Hi-Viz Waist coat, Hard Hat, Goggles, Respirator, face mask, ear plugs, ear defeders, gloves (different types of gloves).
"Have knowledge of how and where to turn off main supplies"
Show and Tell, there are some great videos on You Tube if you don't mind taking a laptop down, or physically do it in your scout hut, Identify where they are and show them how to turn them off. Make sure you explain why. Also explain not to do this at home.
See attachment (Utilities Card Game) not for everyone but a fun game to get them thinking about the mains supplies
Base 4 (optional - dependant on numbers/time)
Use attached sheet (Puzzles) for DIY cross word & word search (Leaders Notes) for answers
Base 5 (optional - dependant on numbers/time)
Get the scouts to make a list of DIY that needs doing around the Scout hut. (They could use this for their Major Project) plan a Saturday to come back and the scouts can complete the list.