100% nicotine liquid refers to a solution where nicotine is the sole component, without any dilution or additional substances. It is highly concentrated and should be handled with extreme care due to its potency and potential toxicity. This type of liquid nicotine is commonly used in the production of e-liquids for vaping, where it is mixed with other ingredients to create the desired nicotine strength. When handling or using 100% nicotine liquid, it's crucial to follow safety precautions and dilute it appropriately to ensure safe consumption.