Yeah its safe, if you see him chewing more I'd take it out for the time being until you can occupy him with something else to chew.
The current chews he has might not be the kind of thing he wants to chew. My ham wont chew wood/plastic/cardboard but loves dog treats and monkey nuts. Try lots of different chews and maybe switch them out for different things each clean to give him a different variety, that should keep him busy
