I graduated high school almost twenty years ago, and we weren't allowed to wear jewelry of any type, even watches, during PE or science lab (like chemistry or physics). I saw a guy lose a finger when his class ring got caught in a basketball net. It's a fairly standard, straightforward precaution.
Much ado about nothing.
Psst! You kin take it off for those occasions. That's why the bureaucrat who talked about the reason being the hazard is lying.
I'll bet headscarves are a bear if you catch them in a belt sander, too. That's why God invented common sense.
When I was in elementary school, at least half the girls wore pendants (especially First Communion presents), bracelets, and the occasional ring. Dangerous my ***!
Let's not forget the head scarves. Just think of poor Isadora Duncan.