Squalane was introduced as an emollient in the 1950s.[4] While squalane can be found in small quantities in sebaceous secretions (sebum),[6] it is squalene that is most commonly found in nature, most notably in human sebum and the livers of sharks.[6][7] Squalane has low acute toxicity and is not an irritant at the concentrations used in cosmetics (up to 100%).[8]