Sandalwood oil is an essential oil obtained from the steam distillation of chips and billets cut from the heartwood of various species of sandalwood trees (e.g. Santalum album and Santalum spicatum).
The composition of the oil will depend on the species, region grown, age of tree, and possibly the season of harvest and details of the extraction process used.
Sandalwood oil contains more than 90% sesquiterpenic alcohols of which 50-60% is the tricyclic α-santalol. β-Santalol comprises 20-25%.
Current ISO standards for S. album oil, are 41-55 % α-santalol and 16-24 % β–santalol (ISO 3518: 2002E).