NTP finds that cedarwood oil causes skin lesions in mice and rats
National Toxicology Program (NTP) researchers and collaborators have revealed that cedarwood oil, a fragrance material used in many household products, can cause lesions to the skins of mice and rats in a dose-dependent manner. The finding raises concerns over current widespread human exposure to cedarwood oil and may help scientists develop guidelines for its daily use.
As an essential oil extracted from cedar, cedarwood oil is generally considered harmless and commonly used in insect repellents and personal products, including perfumes, lotions, and soaps. However, some data have implied potential adverse effects for the extract and its components in animals or humans.
In the 3-month study, researchers applied concentrations of cedarwood oil varying from 0 to 100 percent to the skins of mice and rats. The treatment led to reduced body weight and survival, and the animals developed systemic inflammation and skin lesions, including irritations, thickened skin, and ulcerations. The severity of the lesions increased with higher doses, with the mice exhibiting more severe symptoms than the rats. The oil concentrations that caused skin lesions in the rodents are used in products on the market, suggesting that the amount of cedarwood oil in consumer goods is a cause for concern. (QX)
Citation: Catlin NR, Herbert R, Janardhan K, Hejtmancik MR, Fomby LM, Vallant M, Kissling GE, DeVito MJ. 2016. Dose-response assessment of the dermal toxicity of Virginia cedarwood oil in F344/N rats and B6C3F1/N mice. Food Chem Toxicol 98(Pt B):159−168.