A few good punches there and the tattoo ink could smear.

Further, it is the first tattoo ink to be developed in the United States with medical trials for safety testing.

Almost £1,000 was spent buying tattoo ink and a further £1,394 on sun bed equipment for two separate studies.

Some medical practitioners have recommended greater regulation of pigments used in tattoo ink.

The wide range of pigments currently used in tattoo inks may create unforeseen health problems.

But what isn't clear is the safety of tattoo inks.

"I would think tattoo ink would light up like neon," Marino said.

But I always thought that tattoo ink was injected under the skin, where it couldn't blur.

She thinks that the chemical came from the tattoo ink and wants them both to head to the hospital to be tested.

For example, the agency has conducted research on skin absorption of cosmetic ingredients, tattoo inks, and potential contaminants.