The Food and Drug Administration has received complaints from people who have received products marketed as henna temporary tattoos, especially so-called "black henna," at places such as salons and kiosks at beaches and fairs. There have been reports of allergic reactions, skin irritations, infections, and even scarring. "Black henna" may contain the added "coal tar" color, p-phenylenediamine, also known as PPD, which can cause allergic reactions in some people. Henna itself is made from a plant and typically produces a brown, orange-brown, or reddish-brown tint. Other ingredients must be added to produce other colors. Even brown shades of products marketed as henna may contain other ingredients intended to make them darker or make the stain last longer. While the FDA has approved henna for coloring hair, and PPD is used in cosmetics as a hair dye, neither of these color additives is approved for direct application to the skin. Read more about summer safety for you and your kids.