Absolutely not suitable for hamsters!
As soon as I started breaking up the wood shavings with my hands, I scratched myself on a splinter. I checked carefully and in less than 7cm of compressed shavings I found loads of large, stiff splinters, absolutely not suitable for letting a hamster go through, since it should be able to dig tunnels and make itself a nest. I'll break up a bit more, being extremely careful, only because I need it urgently, but I expect to throw almost all of it away.