In September 2019 researchers from the Cosmetic Ingredient Review Expert Panel in the USA published their safety assessment of 14 citrus-derived peel oil ingredients. These ingredients are most frequently used in cosmetics as fragrances and/or skin conditioning agents. The Panel reviewed relevant studies related to these substances and concluded that these ingredients are safe for use in cosmetic products when the finished products, excluding rinse-off products, do not contain more than 0.0015% (15 ppm) 5-methoxypsoralen, and when formulated to be non-sensitizing and non-irritating. The Panel stated that as final product formulations may contain multiple botanicals, each containing the same substances of concern, manufacturers of cosmetics should be aware of these substances to avoid them reaching levels that may lead to sensitization or other adverse effects. The Panel stated that the cosmetics industry should continue to use good manufacturing practices to limit impurities.
Burnett CL et al. Safety Assessment of Citrus-Derived Peel Oils as Used in Cosmetics. Int J Toxicol. 2019 Sep/Oct;38(2_suppl):33S-59S