I dunno about silicone, but with plastic you want to avoid plastic softeners. That's the real nasty stuff. Pure nylon oven bags are suitable. Keep in mind super

I dunno about silicone, but with plastic you want to avoid plastic softeners. That's the real nasty stuff. Pure nylon oven bags are suitable. Keep in mind supermarket oven bags likely won't be pure nylon. I use the nylon bag material made for Volcano vaporizers by storz & bickel, because I know it has no plastic softeners.