While lead is not intentionally added as an ingredient, trace amounts of lead can sometimes be found in lipstick and other cosmetics as a contaminant. This is because lead is a naturally occurring element that can be present in the raw materials used to make the pigments and other ingredients.
It's important to note that the levels of lead found in lipstick are typically very low and are generally considered to be safe by regulatory agencies like the FDA. The FDA has set a maximum allowable level of lead in color additives used in cosmetics, and they regularly test cosmetic products to ensure they meet these standards.
Even though the levels are low, there is no safe level of lead exposure. Lead can be dangerous, especially for pregnant women and children. The FDA has published studies that show that the levels of lead found in lipstick are not a health risk, but many organizations are still lobbying to get the levels of lead in cosmetics reduced to zero.
The Campaign for Safe Cosmetics is one such organization.