Carsten R. HamannWaranya BoonchaiLiping WenEmi Nishijima SakanashiChia Yu ChuKylin HamannCurtis P. HamannKumar SinniahDathan HamannLoma Linda University School of MedicineMahidol UniversityPeking Union Medical CollegeTokyo Medical and Dental UniversityNational Taiwan University HospitalCalvin CollegeContact Dermatitis InstituteUniversity of Arizona2018-11-092018-11-092014-02-01Journal of the American Academy of Dermatology. Vol.70, No.2 (2014), 281-28710976787019096222-s2.0-84892668554https://repository.li.mahidol.ac.th/handle/20.500.14594/34308Background Cosmetic skin lightening is practiced worldwide. Mercury is a well-documented melanotoxin added to some lightening products. However, mercury can cause many dermatologic, renal, and neurologic problems. The Food and Drug Administration limits the amount of mercury in cosmetic products to trace amounts, 1 ppm. Objective The objective of this study was to quantitatively evaluate a large international sample of lightening products for mercury content, focusing on products available to US consumers either online or in stores. Methods A total of 549 skin-lightening products, manufactured in 32 countries, were purchased online in the United States, Taiwan, and Japan and in stores in the United States, China, Taiwan, Thailand, Japan, and Sri Lanka. Cosmetics were screened for mercury content above 200 ppm using a low-cost portable x-ray fluorescence spectrometer. Results Of the 549 tested products, 6.0% (n = 33) contained mercury above 1000 ppm. In all, 45% of mercury-containing samples contained mercury in excess of 10,000 ppm. Of lightening products purchased in the United States, 3.3% were found to contain mercury in excess of 1000 ppm. Limitations Our study did not evaluate creams for other melanosuppressive ingredients. Only 1 sample of each product was tested. Conclusion Our study confirms the national and global presence of mercury in skin-lightening products. © 2013 by the American Academy of Dermatology, Inc.Mahidol UniversityMedicineArticleSCOPUS10.1016/j.jaad.2013.09.050