Here is a post about lasers and chrome-tanned leather (with cited sources) that seems to do some due diligence, but I’m no chemist so I can’t really confirm: https://groups.google.com/g/heatsynclabs/c/JGRst9GxPUk/m/9Pa1qG5_UvMJ
He does mention the possibility of damage to certain types of metals that may or may not come into contact with the smoke.
the ATX Hackerspace laser safety guide does not mention tanning method, just pretty much says real leather is safe but can tricky.
Another makerspace (I can’t remember which) had chrome-tanned on the “don’t cut” list with the note that it shriveled and deformed when lasered.
Another thing to consider is just how terrible the chrome-tanning process is for the environment.
This post goes into that a little bit… but of course it is from a leather company that uses natural methods and is promoting their process/product over others.
here is an NIH publication that talks about the hazardous materials found in a laser-induced breakdown spectroscopy (LIBS) of chrome-tanned leather.
Granted, they are using a Yag laser, not C02, but it seems relevant to me: laser the leather and measure what comes out.
It’s nasty. If you roll coal, flush your old medications, and dump your used motor oil in the drain, you probably don’t care. If you do care about the environment, maybe avoid the chrome stuff, and get veg-tanned. Or, even better, get brain-tanned.
Brain tanning : Basically, the brain can be used for all animals. Usually, the brain mass of an animal is enough to make leather from its skin. It is available at the slaughterhouse or butcher, if one does not have the head of the animal. Brain is quickly perishable. Therefore, needs to be used immediately or must be frozen. Approximately 300 grams of brain mass is needed for a deer skin.
Variations of these methods are still used by do-it-yourself outdoorsmen to tan hides. The use of brains and the idea that each animal (except buffalo) has just enough brains for the tanning process have led to the saying “Every animal has just enough brain to preserve its own hide, dead or alive.”