Is Copper pipe safe?

I'm designing an activity centre for my Chinchillas (as yet unborn :impatient:) to keep myself occupied while I wait :rofl: and I was wondering about using copper pipe with sisal/seagrass wrapped tightly round it.
Also I've seen raffia for Chinchilla's is this safe? If yes I was thinking of crocheting mats to sleep on and chew up :D (not one with holes! Don't want tiny paws getting caught).
:thanks: for all the help I've had to other questions