I have a friend who makes gun holsters out of Kydex. I was researching to see if it was suitable material to laser and I came across a very good pictorial warning on what lasering deadly vinyl can do. I had read the warnings about PVC vinyls, but hadn’t seen the actual damage. If it can do this to metal, imagine the damage to your lungs. Be careful and use due diligence when putting material in your laser!
edited to add 2nd pic…forgot it the first time