If you inhale the fumes from cotton as it
IS burning then it is not only unpleasant but Im assuming it can be pretty damaging. Once the cotton is burnt however, I do not know what harmful effects there are....but it does taste nasty and its harmful effects are not the point for me, I just wont use it anymore and will rewick it(I use RDAs), if I were using a prefab tank with a burnt coil then Id replace the coil.
Also....I too vape PG/VG/nic and flavor concentrates...not oil
