Benzyl benzoate is an organic chemical compound characterized as an ester, formed from benzyl alcohol and benzoic acid. It typically appears as a clear, colorless, oily liquid with a faint, sweet, balsamic aroma. While it remains a liquid above 17°C, it can solidify into white flakes or crystals at lower temperatures. This compound exhibits very low solubility in water but dissolves well in organic solvents like ethanol and chloroform.
Treating Scabies and Lice
One of the primary applications for benzyl benzoate is as a topical treatment for parasitic infestations, specifically scabies and lice. Scabies, caused by the Sarcoptes scabiei mite, and lice infestations lead to intense itching and skin irritation. Benzyl benzoate works by penetrating the exoskeleton of these ectoparasites, acting as a neurotoxin that disrupts their nervous system, leading to paralysis and eventual death. It is also toxic to mite ova.
For treating scabies, benzyl benzoate is commonly formulated as a 25% emulsion or lotion. The typical application involves applying the medicine from the neck down to cover the entire skin surface, ensuring all folds and crevices are thoroughly treated. The treatment is usually left on the skin for 24 hours before being washed off with warm water and soap. A second application after 24 hours or seven days is often recommended to ensure complete eradication and prevent re-infestation, as the medication may not kill all eggs.
When used for lice, the lotion is applied to the affected areas, such as the hair and scalp, and left for 24 hours before washing. While effective, it is sometimes considered a second-line treatment due to potential skin irritation. Diluting the concentration for children is sometimes suggested, but this can also reduce its effectiveness.
Applications in Personal Care and Fragrance
Benzyl benzoate is incorporated into personal care products and fragrances. It serves as a fragrance ingredient with a mild, sweet, and balsamic scent. Beyond its own aroma, it functions as a fixative in perfumes and colognes. As a fixative, it helps to slow down the evaporation of other volatile fragrance components, thereby prolonging the overall scent of the product.
It also acts as a solvent for fragrance materials and active ingredients in cosmetic formulations. Its ability to dissolve a variety of compounds makes it useful in creating homogenous mixtures in products. It is found in consumer goods like soaps, lotions, and other cosmetic items, contributing to their scent and texture.
Industrial and Chemical Solvent Uses
Beyond medicine and personal care, benzyl benzoate is used as an industrial and chemical solvent. It effectively dissolves compounds such as cellulose acetate, nitrocellulose, synthetic resins, and certain dyes. This solvent capability makes it useful in the production of lacquers, coatings, and adhesives.
Benzyl benzoate is also employed as a plasticizer in the manufacturing of plastics and rubber. As a plasticizer, it is added to polymers to enhance their flexibility, workability, and durability by reducing their glass transition temperature. This allows for the creation of softer and more malleable materials, used in products like PVC, nylon, and synthetic rubber. In veterinary medicine, it treats parasitic mites in animals, such as mange in dogs. It is also used as an insect repellent against chiggers, ticks, and mosquitoes.
Important Safety Information
While effective, potential side effects and safety precautions should be considered. The most common adverse reactions are localized to the skin, including irritation, redness, burning, and itching, particularly with higher concentrations or prolonged use. Some individuals may experience more severe reactions such as blistering, oozing, scaling, or allergic contact dermatitis. Accidental contact with eyes or mucous membranes can cause irritation.
Do not apply benzyl benzoate to broken, inflamed, or severely damaged skin, as this can increase absorption and potentially lead to rare systemic side effects. Systemic effects from excessive absorption might include headache, dizziness, nausea, or even convulsions in severe cases. For very young children, it is generally not recommended; if used, dilution is often required, which can reduce effectiveness. Pregnant or lactating individuals should consult a healthcare professional before use to weigh the potential benefits against any risks, and breastfeeding should be suspended after application until the product is washed off.
Proper storage and handling ensure safety and product integrity. Benzyl benzoate should be stored in a tightly closed container at room temperature, away from heat, moisture, and direct light, and protected from freezing. Always use the product only as directed and avoid applying more than recommended, as this increases the chance of side effects. Consult a healthcare professional before using benzyl benzoate, especially for medical conditions, to ensure appropriate and safe application.