Is safe to reuse plastic bags used for sous vide
There is not safety issue as long as you clean well. It shouldn't be a problem after most cooks.  If using high heat...or very long cooks, you might check the integrity of the bag.  Otherwise, I suppose you could wash and dry.  I mainly use zip lock-type bags and discard after each cook, simply because they are a p-i-t-a to clean.