There was a post like last week I think talking about using the cement tubes and putting sand paper in the bottom.....so the buns can run though them....Well I just talked to a friend of the family who works in construction and he said that most of the stuff they use is recycled and because its going in the ground they don't worry about what goes in it....He said that he wouldn't use it around any person or animal who would likely chew on it....

He said that they have plastic tubes and that would be safer to use. ...

So I would just be very careful with the tubes...

Good luck, guys.

Well, I guess no cardboard product is meant for consumption, be it cardboard boxes or toilet paper rolls, etc. Some of that stuff is made from recyclables too. So, I don't know... 

Anyway, thanks for the heads up, can't be careful enough with bunnies!

I'm pretty sure no cardboard is meant for consumption, which is why it's recommended if your rabbit actually eats vs shreds the cardboard to remove it.

Normally cardboard that does not have a wax coating, or is not covered with some ink based writing or coloring is generally safe and digestible.  Quoting Dana Krempels "As long as the paper and cardboard have no print containing heavy metals (as many colored inks do), there is no harm in your bunny eating it.  Paper is made of cellulose, which is digestible to rabbits." 

Source: http://en.allexperts.com/q/Rabbits-...aper-2.htm

And of course, you don't want your bunny filling up on paper and forgoing his diet, that would be what you need to really watch out for more than anything. 

HOWEVER, you bring up something to think about regarding the cement tubes.  IF what he is saying is a bunch of junk is mixed in the recycled paper to make the tube, then that would be concerning!