California Department of Public Health (CDPH) scientists have reportedly identified a new method of screening product samples to determine mercury contents in skin-lightening creams. According to Gordon Vrdoljak of CDPH, some of the creams have been found to contain mercury levels as high as 210,000 parts per million (ppm) despite the U.S. limit of 1 ppm. “If people are using the product quite regularly,” he said in an August 13, 2014, press release from the American Chemical Society (ACS), “their hands will exude it, it will get in their food, on their countertops, on the sheets their kids sleep on.”

The new method reportedly involves a machine that employs a technique called total reflection x-ray fluorescence, which apparently runs between 20 or 30 samples each day, while a previous technique could take several days to show results, said Vrdoljak. The ACS press release noted that mercury can successfully lighten skin—which may explain the lightening products’ popularity— but may, at excessive exposure levels, cause several health problems, including kidney damage, headaches, fatigue, depression, and lower cognitive functioning. The skin-lightening creams are apparently popular in Asia, Central America, Africa, and the Middle East, and American visitors to those regions may bring the products back with them for personal use. See ACS Press Release, August 13, 2014.