I think this thread has been slightly hijacked but on that subject:
I had an operator come up to me complaining about the new QA manager's new rule about no ball caps when I was a tech at a previous role. Knowing the operators sure does help a lot with these types of situations.
This particular operator was a country boy. He liked mudding, hunting, and all of that country living kind of stuff.
I took one look at him and said "Well we look at it this way. How often do you wear that hat?"
He indicated that he wore his hat all of the time.
I asked "Do you wear it when you go mudding and hunting?"
He indicated that he did.
I asked "How much blood and mud have gotten on the hat?"
He stared at me blankly.
I then set on explaining that if there was blood on the hat it could cause a pathogen risk and that if there was mud on his hat it could have salmonella all over it not to mention all of the other risks it could pose.
That was the moment he understood why he couldn't wear his hat on the floor and is the reason I advocate against people wearing any kind of hat/ball cap (other than as previously stated) while working.