The U.S. Food and Drug administration is warning shoppers to check their hair dye products for lead after passing a ban on the ingredient.
As of last month, hair dyes were the last consumer product where lead was still allowed to be used as an ingredient, despite the fact that it was already banned entirely in Canada and the European union.
But after decades of debate, that it finally changing.
"There is no longer a reasonable certainty of no harm from the approved use of lead acetate in hair coloring products," the agency said in a statement.
Lead is a neurotoxic chemical, which can damage the brain and other organs, and also causes high blood pressure in adults and stunted growth in children.
While it was approved for use in hair dyes in the 1980s, the FDA says there were "deficiencies" in studies that demonstrated it was safe.
The Centers for Disease Control and Prevention (CDC) warn there is no safe level for lead exposure, but for decades lead acetate has been a key ingredient in many brands of men's hair dye.
While there is no recall in effect, the FDA is now warning anyone who still has dye with lead acetate as an ingredient in their home not to use it, and to check the ingredients list on new packages for lead.
They also set a 12-month deadline for companies that still use lead acetate to change their formulas.
The environmental charity Environmental Working Group says at least two major brands still on sale have included lead acetate in their formulas: Grecian Formula and Youthair.
EWG's Skin Deep database also listed lead acetate as an ingredient in Restoria hair dye
Combe, Grecian Formula's parent company, claims they stopped using lead acetate "some time ago."
But products containing lead acetate may still be sold before next year's deadline, and older stock available through online stores may still contain lead.
Companies that continue to sell products containing lead acetate before the deadline passes will only be required to add a new warning label to their bottles.
Both Grecian Formula and Youthair are already available in varieties that use bismuth citrate, not lead, so making the switch to a safer product is easy.