This was recently discussed in this thread.
http://www.canreef.com/vbulletin/sho...t=91807&page=4
I wasn't sure either if it was safe, so I started using a product from the local pool and spa shop called Aqua Neutralizer which removes chlorine and bromine from water. It contains sodium sulphite. It seems to work as the socks no longer carry the bleach smell after a soak in water with Aqua Neutralizer. I still let them dry out well before use again.