Essential oils that may be toxic to the liver, when swallowed
Aniseed
Basil
Bay
Buchu
Cassia
Cinnamon (bark and leaves)
Clove
Fennel
Tarragon
The oils listed underneath are banned and can cause toxicity if taken internally as well as dermally (in a massage blend)
Almond (Bitter)
Boldo leaf
Calamus
Camphor
Horseradish
Jaborandi leaf
Mugwort
Mustard
Nightshade
Pennyroyal (both European and North American)
Rue
Sassafras
Savin
Southernwood
Stinging nettles
Tansy
Thuja
Wintergreen
Wormseed
Wormwood