Study Finds Bacteria in Commercial Tattoo and Permanent Makeup Inks

Commercial tattoo and permanent makeup inks have been found to contain both aerobic and anaerobic bacteria by researchers. The results, published in Applied and Environmental Microbiology, a journal of the American Society for Microbiology, indicate that tattoo inks may pose a risk of human infections. This study is significant because it is the first to examine the occurrence of anaerobic bacteria in commercially available tattoo inks.

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.”

Seong-Jae (Peter) Kim, Ph.D., Corresponding Author and Microbiologist, Division of Microbiology, National Center for Toxicological Research, U.S. Food and Drug Administration

Kim adds, “This suggests that contaminated tattoo inks could be a source of infection from both types of bacteria. The results emphasize the importance of monitoring these products for both aerobic and anaerobic bacteria, including possibly pathogenic microorganisms.”

The new study's primary objective was to determine the frequency of anaerobic and aerobic microbial contaminants in tattoo inks that are sold in the United States. The scientists combined 1-2 grams of tattoo ink solution with suitable media and cultivated the bacteria in a standard incubator to detect aerobic bacteria.

For the detection of anaerobic bacteria, they combined the ink solution with suitable media and cultivated the bacteria in an anaerobic chamber, a device made expressly to cultivate anaerobes.

By continuously flushing this chamber with a mixture of gases, including nitrogen, carbon dioxide, and hydrogen, oxygen is kept out of it. This process was carried out by the researchers on a total of 75 tattoo inks made by 14 different manufacturers.

The investigators found that approximately 35% of tattoo or permanent makeup inks that were sold in the United States had bacterial contamination.

Kim said, “Both types of bacteria, those needing oxygen (aerobic) and those not needing oxygen (anaerobic), can contaminate the inks. There was no clear link between a product label claiming sterility and the actual absence of bacterial contamination.”

The rising popularity of tattooing in recent years has coincided with an increase in tattoo-related complications or adverse reactions. It should be noted that microbial infections constitute just 1 aspect of these complications. In addition to microbial infections, immunologic complications, such as inflammatory reactions and allergic hypersensitivity, as well as toxic responses, represent a significant portion of these issues.”

Seong-Jae (Peter) Kim, Ph.D., Corresponding Author and Microbiologist, Division of Microbiology, National Center for Toxicological Research, U.S. Food and Drug Administration

Kim notes, “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.”

There are two main avenues in which Kim and associates plan to advance the research. The team will create more effective microbiological detection techniques for tattoo inks, which will speed up, improve accuracy, and require less work.

To improve the knowledge of microbial contamination in tattoo and permanent makeup inks, the team will also carry out methodical research. To avoid contamination in these products, it is imperative that the occurrence, co-occurrence, and diversity of microbial contaminants be studied.