HR be hanged... No offense to HR persons . If your risk analysis determines it is a food safety risk (which it almost certainly is) disallowing them is the only reasonable recourse. Unless you want to create grey areas and unrest over inequality among the production employees (different rules for one than another) you need to make it a hard and fast rule "no hair decorations or additions". That would include hair weaves, beads, barrettes bows etc. Hair nets are just not designed to keep those items inside. I have found if the employees are given direct evidence for the decision and given specific expectations, they're usually willing to comply. We just added false eye lashes to our GMPs last year and I had to tell an employee her $150.00 "permanent" eyelash extensions would have to go and told her why. She didn't like it but she complied because she understood our food safety culture and the reason for the decision. She had also just gotten $100.00 of new nail veneers and lacquer which also had to be taken off that night. Tough to do but your food safety initiatives have to be solid and enforced consistently. Just my .02
I agree with this post. My only difference would be with hair weaves.
You are not going to be able to tell who has a hair weave or not. I don't wear them personally, but from my understanding, they are sewn in. Also, if those are not allowed, then wigs are not allowed either...as those are definitely detachable. I'm not going to survey my employees to find out if they wear weaves or wigs. A hairnet, or even a hairnet with a kerchief will suffice in this case.
To the OP though, I would not allow beads or barrettes and make this part of my policy. I would also include HR because regardless of the food safety initiatives, people claiming discrimination is a real thing and I personally would not want to have to deal with that.