[z2]

I currently do something like this with a cheap thermal printer. Aside from apparent environmental issues of thermal paper, it is really great to print out these short, portable, and disposable materials on a whim from my phone (Bluetooth) and computer (USB).

[TheSpiceIsLife]

The reactant in thermal paper is often BPA.

Might pay to check yours and read the health effects section here https://en.wikipedia.org/wiki/Bisphenol_A

Edit: fixed a word

[rtkwe]

Couldn't tell but is BPA toxic on skin contact. All the worry I was hearing was based on ingestion.

[saurik]

Do a Google search for "BPA toxic skin contact" (search terms you came up with) and be amazed at the wonder of modern search engines (which will return results from PubMed, Nature, and WebMD).

(edit) There is something telling about how three people have now downvoted my comment for not doing the work of pasting the links myself, but not a single person has bothered to provide the links themselves, which kind of demonstrates the problem with these comments: the comment I am responding to is undermining a well-researched notion--one that AFAIK no one questions, and for which it is trivial to find numerous articles and studies: that BPA is absorbed through the skin from receipts--with the moral equivalent of "citation needed"; that comment asking for a reference seriously took longer to type than finding the relevant articles would have, and yet in practice is asking other people to do that work, and so the work doesn't get done by anyone... but the comment itself sits there, making people who are less informed on the topic question the validity, as in "I dunno, this comment claims they hadn't heard that, and is demanding citations; if it were easy to find a citation they wouldn't be asking that, so I guess the thing they are poking at isn't actually true". If you want to downvote my response to that behavior--which is to point out that a Google search would have worked--but you aren't willing to actually do the work of providing the links yourself (or at least also downvoting the comment), you are just making yourself part of the problem of incentivizing leaving these misinformative comments :/.

[mrexroad]

I say this to be helpful, so please don’t take it as an attack. While initial comment added no value (e.g. that Google exists), but what I found off-putting was your tone. That, coupled with the comment[0] in your profile, make it easy to jump to a specific conclusion, right or wrong, about your intent. just be mindful of perception. FWIW, I struggle with this daily and often wish more folks would point out when I’m coming across in a way I didn’t intend.

[0] “I make it something of a policy to not look at things people say in response until at least a month later.”

[DenisM]

You are being downvoted for being snarky, which is against the HN guidelines.

[perl4ever]

You are being downvoted for commenting on voting, which is against the HN guidelines.

[samatman]

Commenting on downvotes is against guidelines, while commenting on commenting on downvotes is ok: that's how word gets out not to do this.

Commenting on commenting on commenting on downvotes, which you're doing, is annoying. I'm on an even number here, so I should be okay. We'll see!

[WalterBright]

> The reactant in thermal paper is often BPA.

Too bad. The original "invisible ink" activated by heat is lemon juice.

[TheSpiceIsLife]

I heard this before, but how does that knowledge help with dealing with BPA exposure now?

[WalterBright]

Obviously, it doesn't. But the knowledge of lemon juice is something you can pressure your thermal printer vendor with.

[int_19h]

Or milk.