I think what simply could be taken from what you said is: wash your hands after you handle that stuff because it can kill your fish.I'm stating nicotine in a concentration of mg/ml. Most nicotine concentrations are listed on the bottle as a percentage of concentration. A 1.2% nicotine concentration equals 12mg/ml.
The most popular concentration for smokers who smoked a pack a day is 24mg/ml. Concentrations as high as 36mg/ml are offered in commercial sales.