KARLSRUHE, Germany — One in three tattoos in Germany contain unpermitted substances and two in three contain technical ink such as automotive paint or printer ink, a government study said on Friday.

The Chemical and Veterinarian Medicine Investigation (CVUA) office in Karlsruhe, Germany said samples of tattoo ink it inspected showed cancer-causing materials, including carbon black which is often used in automobile tires and printer toner.

Two-thirds of tattoo ink tested contained dangerous materials that are not illegal but also not intended to be injected into people's skin, said the CVUA, a department of the health ministry in southern state Baden-Wuerttemberg.