Essential oil which is then collected in the receiving vessel. Most oils are distilled in a single process. One exception is "ylang-ylang" ("Cananga odorata") which is purifed through a fractional distillation. The recondensed water is referred to as a hydrosol, hydrolat, herbal distillate, or plant water essence, which may be sold as another fragrant product. Hydrosols include rose water, lavender water, lemon balm, clary sage, and orange blossom water. The use of herbal distillates in cosmetics is increasing. Most citrus peel oils are expressed mechanically or cold-pressed (similar to olive oil extraction). Due to the relatively large quantities of oil in citrus
Essential oil may contain impurities and additives that may be harmful to pregnant women. Sensitivity to certain smells may cause pregnant women to have adverse side effects with essential oil use, such as headache, vertigo, and nausea. Pregnant women often report an abnormal sensitivity to smells and taste, and essential oils can cause irritation and nausea when ingested. Always consult a doctor before use. The following table lists the or median lethal dose for common oils; this is the dose required to kill half the members of a tested animal population. LD is intended as a guideline only, and reported values can