Essential oil characteristics and effects, but also the products of the very same tree can vary grossly. Lavender oil has long been used in the production of perfume. However, it can be estrogenic and antiandrogenic, causing problems for prepubescent boys and pregnant women, in particular. Lavender essential oil is also used as an insect repellent. Rose oil is produced from the petals of "Rosa damascena" and "Rosa centifolia". Steam-distilled rose oil is known as "rose otto", while the solvent extracted product is known as "rose absolute". The potential danger of an essential oil is sometimes relative to its level or grade of
Essential oil peel and low cost to grow and harvest the raw materials, citrus-fruit oils are cheaper than most other essential oils. Lemon or sweet orange oils are obtained as byproducts of the citrus industry. Before the discovery of distillation, all essential oils were extracted by pressing. Most flowers contain too little volatile oil to undergo expression, but their chemical components are too delicate and easily denatured by the high heat used in steam distillation. Instead, a solvent such as hexane or supercritical carbon dioxide is used to extract the oils. Extracts from hexane and other hydrophobic solvents are called "concretes", which