I've used these things for years with absolutely no problems.
Obviously you have to be reasonable with what you use, some cardboard packaging has very waxy coating and should be avoided. I'm no expert so i can't explain it well, but i believe a lot of the ink used is 'safe' ink, as in its non-toxic.
Toilet tissue is completely safe, i think worrying about the bleaching is a bit too much
It breaks up very easily and is the safest material to ensure if ingested it wouldn't cause a blockage.
Unless the glue is very noticeable, then the amount is probably very small, it may also be non-toxic glue.
But of course, if you would rather not risk using these that up to you
Its just a risk most of us take if we've never experienced problems.
You could maybe contact companies and ask about their packaging materials used?