This is a rough concern. Because employing a sub-ohm tank with something as dense in nicotine as salt nic e-liquid will induce nicotine toxicity/overdose, vaping nicotine salts is ideal done that has a pod process package. To put it yet another way, don't use sub-tanks to vape with Nic Salt. https://jeffreykjmlk.thenerdsblog.com/32051856/the-basic-principles-of-vape-pods