Getting inked could make you sick.

In a first-of-its-kind study, researchers detected bacteria in commercial tattoo and permanent makeup inks, demonstrating that they could cause human infections.

"Our findings reveal that unopened and sealed tattoo inks can harbor anaerobic bacteria, known to thrive in low-oxygen environments like the dermal layer of the skin, alongside aerobic bacteria," said researcher Seong-Jae (Peter) Kim, a microbiologist at the National Center for Toxicological Research at the U.S. Food and Drug Administration. 

"This suggests that contaminated tattoo inks could be a source of infection from both types of bacteria," he added. 

The findings were published July 2 in the journal Applied and Environmental Microbiology, a journal of the American Society for Microbiology.

The researchers' goal was to gauge the prevalence of microbial contaminants in tattoo inks in the U.S. market.

Kim said the findings emphasize the importance of monitoring the inks for bacteria and microorganisms.

The team used a standard incubator and an anaerobic chamber to test ink solutions for bacteria. The incubator was used to look for aerobic bacteria, which need oxygen to thrive. The anaerobic chamber provided conditions ideal for bacteria that don't need oxygen. 

"Both types of bacteria, those needing oxygen [aerobic] and those not needing oxygen [anaerobic], can contaminate the inks," Kim said in a journal news release.

His team tested 75 tattoo inks from 14 manufacturers. In all, about 35% of tattoo or permanent makeup inks sold in the United States were contaminated with bacteria, they found.

Kim added that microbial infections aren't the only issue with the inks. Complications such as inflammatory and allergic reactions, as well as toxic responses, are other risks, he noted. 

"In light of our study results, we want to emphasize the importance of continuously monitoring these products to ensure the microbial safety of tattoo inks,"  Kim said.

His team plans to continue working on two fronts. They will look to develop faster, more accurate and less labor-intensive ways to detect microbes in tattoo inks. They also plan to dig deeper into the diversity of microbial contaminants, in a bid to prevent tainting of the products.