"99% nicotine" typically refers to a highly concentrated form of nicotine used in various industries, including pharmaceuticals and vaping. This designation indicates that the product is 99% pure nicotine, with minimal impurities. However, it's important to note that even at this high level of purity, nicotine is a potent and potentially toxic substance that should be handled with extreme caution. Proper safety precautions should be followed when working with 99% nicotine, and it should be stored securely away from children and pets. Additionally, dilution with other substances such as propylene glycol (PG) and/or vegetable glycerin (VG) may be necessary to achieve the desired nicotine strength for vaping purposes.