Disclaimer: When there is an economy, I'm an engineer not a chemist or MatSci person... but I know that PVC degrades in some way when exposed to UV light. I also know that some people heat, mold, and "burn" PVC to make interesting looking perches and climbing branches. My question is, does anyone know the full extent of the chemical changes of PVC - especially when exposed to UV light or being "burnt" for color change? (I know a lot of PVC is coated on the outside to protect it from UV light, but is that coating safe? It's not like potable water is supposed to be on the outside...)

I'd like to set up more climbing areas in my exo, but it gets some UVB bleed from the leo's light. My husband has been looking at the "burnt" PVC for his future snake, but I'm concerned humidity in those enclosures could leech out any released chemicals. Any input would be appreciated and thanks in advance!