[AmityvilleHams]

It doesn't always happen,but it is highly likely.

Plastic is heavily debated,interestingly enough.It is not breathable like wood and some other materials,so it could cause respiratory problems(mostly plastic igloos and tubes).The majority of hamsters will chew just about anything in their enclosure,hence a second reason for plastic being avoided.

If they're plastic,they're not edible and are therefore unsafe unless you have the extremely rare hamster that somehow doesn't chew plastic.

I don't think would be that shocking to have something marketed towards small pets be unsafe,considering how many things even from high quality brands are actually unsafe for various pets.