What’s in tattoo ink? My team’s chemical analysis found ingredients that aren’t on the label and could cause allergies
- Written by John Swierk, Assistant Professor, Chemistry, Binghamton University, State University of New York

Tattoos are an incredibly common form of permanent self-expression that date back thousands of years. Most tattoo artists follow strict health and sanitation regulations, so you might assume that tattoo inks are carefully regulated, too.
But as work done...