Screw Toy Battery Covers
Screw Toy Battery Covers

I pose the question, "Why do toys made in China have screws locking their battery covers?" Yes, I assume it's to "protect" small children and keep them from swallowing batteries (has that been a huge problem?) but where is the law requiring this?

I can't find anything on the interwebs.

If you know, please leave me a link with sources that can be peer reviewed.