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
Bergamot essential oil directly to the skin via a patch test, followed by exposure to ultraviolet light, a concentration-dependent phototoxic effect is observed. However, if the oil is twice rectified (and therefore bergapten-free), no phototoxic response is observed. The International Fragrance Association (IFRA) restricts the use of bergamot essential oil due to its phototoxic effects. Specifically, IFRA recommends that leave-on skin products be limited to 0.4% bergamot oil, which is more restrictive than any other citrus-based essential oil. Although generally recognized as safe for human consumption, bergamot essential oil contains a significant amount of bergamottin, one of two furanocoumarins believed to be responsible