What is it? Farnesol
Other names: Trimethyl dodecatrienol, 2,6,10Dodecatrien1OL, 3,7,11Trimethyl.
What's it used in? Fragrances, cleansers, moisturisers, deodorants.
What does it do? In perfumes it enhances sweet floral fragrances. It's also used to add flavour to cigarettes and as a pesticide - it kills mites.
Any controversy? It's on the European Union's list of banned and restricted fragrances as a possible human immune system toxicant. Not recommended for people with allergies.