<human>: Is there any way to tell if an e-liquid contains nicotine?
<bot>: Yes, there are several ways you can tell if an e-liquid contains nicotine. First, look for the words "nicotine" or "nicotine salt" on the label. Second, read the ingredients list and see if it includes any of the following words: propylene glycol, vegetable glycerin, nicotine, or diacetyl. Third, take a look at the color of the e-liquid; nicotine is often added as a brown powder. Fourth, smell the e-liquid - if it has a strong odor similar to tobacco smoke, then it likely contains nicotine.