Castor, coconut, and olive oils are not essential oils. Some people actually do consume essential oils, but that is another topic entirely. Essential oils are extremely concentrated as compared to other oils which is part of what makes them dangerous to reptiles, but as mentioned it is also because some of them contain phenols. If a body product lists "lemon oil", "tea tree oil" or anything like that in the ingredients it is referring to an essential oil. Oils that you would use with methods of dilution, diffusing, or in aromatherapy are essential oils. Generally speaking if you wash your hands with plain soap that isn't citrus or tree oil scented prior to handling your snake you should be okay.