The Food and Drug Administration moved to get the lead out of hair products on Tuesday, saying there’s no safe level of lead.

Few hair coloring products on the U.S. market still contain lead, but it had been the main ingredient in dyes sold to gradually re-color gray hair, such as Grecian Formula.

Grecian Formula now uses a compound based on a different metal, bismuth, to darken gray hair, although it's possible to find Grecian Formula products containing lead online.

Other manufacturers should also remove lead, the FDA said.

“In the nearly 40 years since lead acetate was initially approved as a color additive, our understanding of the hazards of lead exposure has evolved significantly. We now know that the approved use of lead acetate in adult hair dyes no longer meets our safety standards,” FDA commissioner Dr. Scott Gottlieb said in a statement.

“Lead exposure can have serious adverse effects on human health, including for children who may be particularly vulnerable.”

So-called progressive hair coloring products gradually darken the hair shaft with a buildup of the metals used as the main ingredient. Lead was effective, but dangerous.

Consumer groups have been pushing for the FDA to act. “The continued use of lead acetate as a hair colorant used in the home will inevitably result in dangerous lead exposure to the user and others in the household, including children and pregnant women who are most vulnerable to permanent harm. FDA must take steps as soon as possible to bring the unsafe use of lead acetate as a hair colorant to an end,” a coalition of 50 environmental groups said in a petition last year.

“The continued use of lead acetate as a hair colorant used in the home will inevitably result in dangerous lead exposure to the user and others in the household, including children and pregnant women who are most vulnerable to permanent harm,” the groups, which included the Public Interest Research Group, the Environmental Working Group and others, said in their petition.

“FDA must take steps as soon as possible to bring the unsafe use of lead acetate as a hair colorant to an end.”

When small children or babies with developing brains are exposed to lead, it can cause permanent damage to brain cells. It can also stunt growth.

In adults, lead exposure can raise blood pressure and damage organs.

There is no safe level of lead exposure and people can take in lead by breathing in dust, drinking it in water or absorbing it through the skin.

The FDA said it would give companies a year to reformulate their products.

In the meantime, people who want to avoid lead in hair dye can read labels,the FDA said.

“Any hair dye product containing lead acetate must also contain the warning statement: ‘Caution: Contains lead acetate. For external use only. Keep this product out of children's reach. Do not use on cut or abraded scalp. If skin irritation develops, discontinue use. Do not use to color mustaches, eyelashes, eyebrows, or hair on parts of the body other than the scalp. Do not get in eyes. Follow instructions carefully and wash hands thoroughly after each use’,” the FDA added.