Does the print on thermal paper disappear after a while if exposed to light?

Not so much light, but heat. read this

The hand sanitizer theory is new to me.

@elbanditoroso Thanks. Your link says:“Since this kind of paper is susceptible to heat and UV light…”
All I know is people should not have that kind of thing to concern themselves with.
Regarding the hand sanitizer, it is not just a theory. Just try putting it on a receipt that you have or will have, and/or some packaging label.
https://www.fluther.com/227319/are-there-hand-sanitizers-that-dont-remove-ink-and-color-from/