As of December 3, 2018, the Food and Drug Administration (FDA) has terminated its approval of lead acetate as a legal color additive in a response to a petition filed by the Environmental Defense Fund, among others. This information was published in the Federal Register.
Lead acetate has been legally used as a color additive in cosmetic hair dyes for decades, being provisionally approved for this use due to the already established approval of metallic salts as a component of hair dye. The status of lead acetate was changed from provisional to permanent in 1980, when the FDA determined the additive did not pose a significant risk to consumers.
After reviewing the peer-reviewed publications provided by the petition, the FDA agreed that due to the limited evidence of lead acetate’s carcinogenic effects in humans, and the sufficient evidence of its carcinogenic effects in animals, as well as the evidence supporting its adverse effects on multiple organs and systems, including the brain and kidneys, there is currently no way to establish a safe level of exposure to the additive. The FDA also agreed with the petition’s assertion that due to the limitations of the study used to establish that a minimal amount of lead acetate could be absorbed through the skin, the study’s results likely underestimated exposure.
Another key factor in this ruling was related to a comparison of mean levels of lead in the blood of the average United States citizen. In 1980, the average steady-state blood lead level of an adult in the United States was approximately 17 µg/dL. In the 2015-2016 National Health and Nutrition Examination Survey (NHANES), it was discovered that the current median blood lead level for adults in the United States has dropped to 0.880 µg/dL (95% CI, 0.810-0.960 µg/dL). This significant national decrease in lead exposure caused the FDA to conclude that it is no longer valid to claim the amount of lead exposure caused by lead acetate in hair dye would be insignificant.
Although the FDA did not agree with the petition’s assertion that typical use of hair dye containing lead acetate would likely lead to ingestion, they did conclude that overall, the available data on the dangers of lead acetate do not support its continued use as a color additive in cosmetics to be used on the scalp.
Food and Drug Administration. Termination of listing of color additive exempt from certification; lead acetate. Fed Regist. 2018; 83(211):54665-54674.