@Jtom
I would REALLY like to see a company try to enforce this. The amount of "things" people need to take with them is legend. Try telling a Type 2 diabetic s/he cannot have an emergency bar of chocolate / fizzy drink at hand, try telling a female she cannot have "ladies products" with her, try telling someone with a heart condition that they cannot have medicines at hand, wow, what crap that company would be in.
In ALL jobs that I have been in there have been lockers, personal storage, etc for the personnel to use.
NEVER have I had to leave my personnal belongings outside of my working environment. Sometimes I have had to change into personal protective gear, but my own stuff has been secured on site in a locked container.