Essential Oils - Some essential oils can be considered as natural preservatives. This is because of their antiseptic qualities. Ti tree, Eucalyptus and Lavender are probably the most well known oils used in this manner.
Grapefruit Seed Extract - This oil is obtained from the crushed seed of the grapefruit. It is reputed to be a natural antibiotic as well as an antiseptic and disinfectant. This is a safe preservative for use in beauty products that contain water.
Neem Oil - This oil is relatively new on the health scene, but it has been used in India for a long time. It is reputed to be antifungal and antibacterial.
Rosemary Extract - is a powerful antioxidant. It also helps to minimize the oxidation and of some vitamins and amino acids.
Vitamin E (d-alpha Tocopherol) - This is probably the most well known natural preservative for oils. It contains antioxidants that can prevent oils from going rancid.