Temporary tattoos, including black henna tattoos, are not risk free and may cause allergic reactions, the US Food and Drug Administration (FDA) has warned.
Cosmetics, including temporary tattoos, do not have to receive FDA approval before they go on the market in the US, while medicines do. However, the colour additives in cosmetics do have to go through FDA approval.
There are a number of temporary tattoos on the market, said Bhakti Petigara Harp, a chemist in the FDA's Office of Cosmetics and Colors.
Beyond the wet-and-press tattoos found in bubble gum machines, there are several types of temporary tattoos that use plant-based and synthetic dyes.
One type uses henna, a paste made from the dried leaves of the lawsonia plant, which is frequently used to paint intricate designs on the hands and feet of Indian and Pakistani brides, 'LiveScience' reported.
Some henna products are mixed with a hair-dye ingredient, p-phenylenediamine (PPD), which gives the remaining designs a black or blue-black colour.
Although they are frequently used for skin designs, neither henna nor PPD are approved by the FDA for use on the skin, the website reported.
Another dye, jagua, derives from the unripened fruit of the Genipa americana, a South American tree. Indigenous people in the Amazon have long used jagua for body decorations, but the dye is newer to the US.
Allergic reactions to these dyes can involve rashes and blisters. Long-term effects might include scarring, skin changes and increased sensitivity to sun, said Katherine Hollinger, an epidemiologist with the FDA Office of Cosmetics and Colors.
