While the benefits of basil have not necessarily proven, there is a huge base of support in the homeopathic field. There is nothing dangerous as far as I have been able to find. So try it, and if it works for you, keep using it.
Basil or basil oil is commonly used in aromatherapy. Some of its uses are for treating bronchitis and colds, sinus congestion, mental fatigue, migraines and nervous tension. It has a slightly sweet licorice aroma.
It is not dangerous to use basil for aromatherapy. In fact, there are many uses of basil in aromatherapy if you believe in that sort of thing. For example, some people believe that basil can help improve your ability to concentrate.
So, if you believe in aromatherapy, there is no reason not to use basil.
Dangerous, not at all!
In fact, one of the most commonly used oil in aromatherapy is basil oil. There are several health problem that are relieved by the basil oil, such as: nausea. loss of appetite, flatulence, fever, sinsusitis, tension, stress, etc.
Of course, if you are allergic to basil, you have to avoid using it in any form, in kitchen or aromatherapy!