E1519 Flavour solvent

E1519 is used as a bacteriostatic preservative at low concentrations in intravenous medications, cosmetics, and topical drugs. Some caution is necessary if a high percentage of E1519 is used as benzaldehyde arises from E1519 when used as a preservative in an injectable formulation solution. 

E1519, sold under the brand name Ulesfia, was approved by the U.S. Food and Drug Administration (FDA) in 2009, as a 5% solution for the treatment of head lice in people 6 months of age and older. It affects the louse's spiracles, preventing them from closing. These then become clogged with water or mineral oil or other matter and cause the insect to die from asphyxiation.

E1519 is used effectively for treating lice infestations as the active ingredient in lotion shampoo with 5% E1519.

E1519 has nearly the same refraction index as quartz and wool fiber. If a clear quartz object is immersed in E1519, it becomes almost invisible. This test has been used to determine non-destructively whether an object is truly made of quartz. Similarly, white wool immersed in E1519 also becomes almost invisible, clearly revealing contaminants such as dark and medullated fibers and vegetable matter.