[jw1224]

Great first article, and very interesting to see someone else using a receipt printer for bite-sized task management!

I have a variety of automations running which print actionable tasks to my receipt printer via a Raspberry Pi. It’s nice having a real-life ticket I can take hold of.

One thing to be aware of if you’re handling receipts frequently: make sure to buy phenol-free thermal paper. Phenol is toxic and some types of it are banned in certain countries.

[laurieherault]

Yes, I think having a tangible task is really important!

Since I’m in Europe, we don’t really have paper with bisphenol anymore, but that’s not the case everywhere.

[cocothem]

What about the ink? What's the keyword to search for nom toxic printer ink/cartridge

[rozab]

Receipt printers don't use ink, instead they use thermal paper which darkens when heated. You can test this by scratching it with your nail, the heat is enough to leave a mark

[gaudystead]

I agree with you on the first part, but are you sure that the heat from the fingernail is what's leaving that mark? I can take a cold object and run it on the receipt paper to get the same effect, so I think that's a different mechanism at play but I'm open to being proven wrong.

[z2]

The developers in the paper only require a small flash of local heat to turn black, which is why thermal printers can print so fast given the time it takes to heat up and cool down the print head. Friction produces enough heat to do that. You can test this by pressing an object down only, or running it very slowly across the surface in comparison.

[joseda-hg]

I thought most receipt printers were thermal, no ink, just heat

[hgomersall]

AFAICT, BPS is still widely used in Europe.

[fauria]

Is there any way of knowing, just by examining it, whether a given thermal paper is toxic or not?

[account42]

Yes, you look at it carefully and if it looks like thermal paper it may be toxic.

If the substances used are known to be toxic is another matter but you won't know that even with a correct label because it takes time for us to find out that new substances are toxic.

[z2]

I think this is the right approach, speaking as someone who went down the rabbit-hole of looking at alternative non-bisphenol or non-phenol image developers. The very little research on the new ones tend to conclude "we don't know if it's toxic in the long term" or in the case of urea-based papers, "it's highly toxic against aquatic life."

To the GP, if the goal is to avoid phenol papers, phenol papers tend to develop deeper black. And in the US, phenol-free papers are new enough the backside often advertises it. Some are very misleadingly labeled BPA-free, which usually means it's made with the very similar and likely equally toxic BPS.

[fauria]

Thank you for your insightful reply, I greatly appreciate it. However, it does not answer my question, unfortunately.