Essential Oils - Birch
Birch – Like wintergreen, sweet birch is made up of almost entirely methyl salicylate. And, like wintergreen, it’s useful for joint pain.
Birch trees are native to North America, mainly southern Canada and the south-eastern USA. Most of the oil is produced in Pennsylvania, USA.
SAFETY DATA – If in high concentrations can be dangerous; people with kidney failure or reduced kidney function should avoid ingesting birch oil and prolonged topical application.
Sourced from The Illustrated Encyclopedia of Essential Oils : The Complete Guide to the Use of Oils in Aromatherapy and Herbalism