Rose oil the aromatics unaltered by heat. Because CO is gas at normal atmospheric pressure, it leaves no trace of itself in the final product. The equipment for CO extraction is expensive, which is reflected in the price of the essential oils obtained from the process. It takes a large amount of rose petals to distill a small amount of essential oil. Depending on extraction method and plant species, the typical yield can be approximately 1:3,000. To mitigate the cost, some dishonest dealers will dilute rose oil with geranium ("Pelargonium graveolens") or palmarosa ("Cymbopogon martinii") essential oils, both of which are rich
Bergamot essential oil painful erythema and bullae on exposed areas of the skin. In one case, six (6) drops of bergamot aromatherapy oil in a bath followed by 20–30 minutes exposure of ultraviolet light from a tanning bed caused a severe burn-like reaction. Bergamot essential oil contains a significant amount of bergapten, a phototoxic substance that gets its name from the bergamot orange. Bergapten, a linear furanocoumarin derived from psoralen, is often found in plants associated with phytophotodermatitis. Note that bergamot essential oil has a higher concentration of bergapten (3000–3600 mg/kg) than any other citrus-based essential oil. When bergamot essential oil is applied