Essential Oils 101 – Toxic Essential Oils to be Avoided


  • Toxic Essential Oils to be Avoided

Toxic Essential Oils to be Avoided

Certain constituents of essential oils are very toxic, particularly to vulnerable people like the old, babies, young children and pregnant women and should not be used on the body in massage therapy nor ingested due to their high oral and dermal (skin) toxicity.

Almond (Bitter)

Prussic acid – also known as cyanide, is the main constituent of bitter almond oil, and even small amounts can be lethal.


The dried leaves are used in herbal medicine, but the oil is powerful and even in very small quantities produces convulsions.


The root of this plant is used in herbal medicine to treat a variety of problems from headaches to vertigo, but the oil contains asorone which is carcinogenic (cancer causing), and oral ingestion can cause convulsions as well as kidney and liver damage.


This herb is used for a series of digestive complaints, yet is a dermal sensitizer and also irritates the mucus membranes.


This oil contains allyl isothiocyanate and is an irritant to the skin, eyes, nose and mucus membranes.


Although this herb has been used for a variety of problems, the oil is toxic, an abortifacient (miscarriage causing) and a neurotoxin.


This oil is not only toxic because of its high content (92% minimum) of allyl isothiocyanate, but is also a skin and mucus membrane irritant.


The pennyroyal herb is used for various ailments including menstrual problems and used as a stimulant, the oil is toxic and an abortifacient (miscarriage causing) and even in small quantities can cause acute liver and lung damage.


Although the herbal use of rue may be helpful, the oil irritates and burns the skin and is toxic, an abortifacient (miscarriage causing),an irritant to the mucus membranes, a neurotoxin and causes sun sensitivity due to phototoxicity.


This herb has been used for rheumatic pains and gout, but the oil is high in safrole (80 – 90%) which is carcinogenic (cancer causing) and it can be lethally toxic even in small amounts.


This oil is toxic as it contains sabinene, sabinol as well as sabinyl acetate, and is a skin irritant and an abortifacient (miscarriage causing).


Tansy oil is high in thujone, which is poisonous and also causes convulsions, vomiting, uterine bleeding and can lead to respiratory arrest and organ failure.


Thuja oil is a powerful abortifacient (miscarriage causing), poison as well as neurotoxin.


The active ingredient in wintergreen oil is methyl salicylate (98%) and although it has been used in ointments for rheumatism and other such complaints, the topical application of this oil, even in diluted blends can be a skin irritant, especially to those sensitive to aspirin.


Wormseed was used to expel round and hookworms, but due to it toxicity to the liver and kidneys, and suppression of heart function, and general toxicity and neurotoxicity it is no longer used.


The active ingredient in wormwood is thujone, which is a convulsant and neurotoxin and the oil also has abortifacient (miscarriage causing) properties.



Information provided is for personal information and interest only, it is not intended to diagnose, treat, cure or prevent any disease and does not offer medical advice or treatment for any condition. It is recommend you consult your doctor or aromatherapist if you are pregnant, nursing, take medication, have any health/medical conditions and want to include using essential oils.