Coumarin has been illegal in the United States since 1954. The ban was put in place due to the fact that eating high concentrations of coumarin can cause liver damage. However, it would take a human to consume about 30 tonka beans before sustaining significant liver damage. Although coumarin is illegal to consume on its own, it is still legal to be added to tobacco and cosmetic products. Additionally, coumarin is still found in soaps and rubber products.