I think there are different grades any cig in USA that is a preroll or whatever has to be sprayed with flame retardant so ppl don't burn down apartments falling sleep smoking. I remember my friends that smoked being like this is the last pack of Marlboro without the flame retardant. Basically they spray fucked up stuff same thing could be true for some weed. When you smoke something it particularized into smallest easily absorbable particles which put that into your bloodstream. I think certain chemicals are safer to use on plants that you eat but when you smoked some of the pesticides like eagle 2020 it turns into cyanide when smoked l don't mind cigars as much tho.