Very Toxic Oils
Aniseed, Mugwort, Pennyroyal, Wintergreen
Be extremely cautious when you must use these oils, using only small amounts and storing them safely away from children.
Cassia, Birch, Cedarwood, Cinnamon Clove, Fennel, Lemon, Thyme
All of these, plus Orange and Eucalyptus can also become increasingly toxic if used repeatedly over a period of time.
Pregnancy – Avoid
Basil, Clary Sage, Hyssop, Juniper- Berry, Marjoram, Pennyroyal, Rosemary and large amounts of Peppermint
Any of them can prematurely induce labor. Also avoid the very toxic and semi-toxic oils, to protect the fetus.
Epilepsy – Avoid
Fennel, Sage and large amounts of Rosemary or Hyssop
These could provoke an unwanted epileptic reaction IF a person has a predisposition to this condition.
Be Aware of the Skin Irritants
All Citrus oils (except Bergamot), Black Pepper, Cinnamon Bark, Citronella, Clove, Ginger, Lemongrass, Melissa, Nutmeg and large amounts of Cinnamon Leaf or Peppermint
Exposure to direct Sunlight should be avoided after application of Bergamot. Otherwise, skin discoloration may result due to increased photosensitivity.
Persons with Asthma should use smaller amounts of any of the essential oils. The amounts can then be increased gradually if there is no sign of an adverse reaction.