What's In Tattoo Ink? Why Scientists Want To Know

Tattoo artists in Europe are fighting a new ban on two commonly-used green and blue pigments, saying that losing these ink ingredients would be a disaster for their industry and their art.

Meanwhile, in the United States, where about a third of Americans have a tattoo, tattoo ink is almost completely unregulated and there's little known about what's in tattoo ink.

Some artists here say the European restrictions don't make any sense.

"It's strange. You almost feel that, how are you only allowed to use certain inks?" says Matt Knopp, owner of Tattoo Paradise in Washington, D.C. "You can't tell me that all these other inks are bad, especially when I'm using them in the states."

For years, individual countries in Europe have required labeling of tattoo ink ingredients and have limited certain chemicals that are thought to cause cancer, damage DNA, or trigger allergic reactions.