If you make claims being the receipts [haha I know] or consider that this type of comment is useless to the rest of us without receipts.

It's the same for lead free solder. Occasional amateur exposure is probably not a major concern, and especially not for adults who won't get pregnant.

Then again, if you're making a thermal printer device for fun that you plan to touch daily, especially if you want to have children using it, who are also likely to touch it with more of their hands and/or get it wet and/or put it or their hands in their mouths, loading the device with phenol-free paper seems sensible, practical and not especially onerous.