The oft quoted number for a fatal dose of nicotine is 30 to 60 mg for an adult. That sounds way too low for a fatal dose in consideration of the following: I have seen reports of clinical trials involving a 42 mg. nicotine patch. Nobody died. I have known people who, when under stress, were smoking as much as 5 packs a day. They did not die, despite the fact that theoretically this would have exposed them to about 100 mg. of nicotine. The origin of the 30 to 60 is an "estimate" taken from a book published in the 1980s. I don't have access to the book itself to determine how they went about making this estimate. This estimate is being used as the basis for statements that liquid containing nicotine should be banned. This information is from Inchem.org Nicotine (PIM) Main risks and target organs So any chemists out there that can give comparative toxicity info? How does an LD50 for a rat usually compare to the LD50 for an adult human?