I would start the habit of the basic safety issues, eye protection, dust mask or dust collection, and ear protection for louder tools, even some sanders can cause hearing damage not so much the loudness they put off its the amount of time your ears are effected to that noise. This is something when I was younger I should have listened to my parents about having my music WAY to loud or being around loud noises when working, I now have permenant hearing loss, I have a constant ringing in my ears, can not here higher pitch tones.
Eye protection is a must, I have had small particles get in my eyes and its no fun and hurts extremely bad no other pain the world then have a eye doctor pull something out of you eyeball from not haveing saftey glasses on or having something liek carb cleaner get in your eye. Hands show them how to keep them safe, out of harms way. I woudl go over safe working practices all the time, get them in habit of putting on safety glasses without thinking about it.
Their ears also may be more sensitive to sound, though there are some neat hearing protection, hunters use these they amplify sound even the smallest sound you can hear, but a loud pop like a gun going off it instantly muffles it. These are nifty to wear, you can still hear but if a sound isover the preset limit in the unit it muffles it.
