One of the reasons why one needs to be careful using them topically. Being they are so highly concentrated they can burn your skin if you do not use them with a carrier oil. The carrier oil will dilute the oil so that it is harder to burn your skin. Also using them neat is a waste. Part of our skin is made up of water and since water and essential oils do not mix all that is going to happen is it will sit onto of the skin and burn and what doesn't burn will evaporate so basically you are not getting the good usage of the oil.
I would also not ingest the oils unless you are working with a highly trained professional clinical aromatherapist with a some sought of medical degree. This professional has the skills and knowledge and experience working with ingesting oils.
I will give you an example of how concentrated and dangerous these oils can be if not used properly.
When I started using essential oils awhile back, I was blending 3 essential oils to be put into a 10ml bottle with carrier oil and I accidentally put one drop of the oil onto my kitchen table. The phone rang and i was talking for 10 minutes and totally forgot i had the oil on the table. When i got off the phone and went to wipe off the oil thinking nothing really would happen, i had a hole in the table about 1/2 inch deep. I used dish detergent and water to wipe out the rest hoping it would not go deeper. Thank goodness i got it in time not to go deeper but now i still had this hole and i definitely was not happy. When my husband came home he filled it in with wood putty, sanded it when it dried and we put a little bit of poly urethane on it to keep it from dissolving every time i cleaned the table.
I learned a very valuable lesson from this. The picture you see here is the hole filled in. This is an oblonged table with 2 leaves. This happened in one of the leaves, that is why you see a line. I like this table a lot and did not want to have to purchase a new table. It has been 7 years since this happened and so far the table is fine. I am wondering what would have happened if i had spilled the entire bottle- ehhhhhhh!! I do not want to even think about it.
I wear gloves when i blend so if i do drop oil at least it is not on my hands. I have occasionally gotten a drop on a shirt and had to throw it out because i tried everything and nothing took the stain out even after i immediacy cleaned it.
So i am telling you all this to be very careful using essential oils, get as much education on them, seek out Qualified Aromatherapists like myself that have the proper education and experience, even we can run into trouble but at least we know what we are doing and how to rectify a situation.