About 1 in 3 tattoo and permanent-makeup inks carried bacteria

Bacteria were found in both types of ink, including products labeled sterile, although the study did not show that any specific product caused an infection.

Editorial illustration — not from the study.

A retrospective analysis of 259 unopened tattoo and permanent-makeup ink products found bacterial contamination in 35.4% of samples across four surveys. Contamination rates were similar for the two types of ink and did not differ significantly by sterility claim or manufacturing origin.

Bacillus was the most commonly isolated group, followed by Pseudomonas, Staphylococcus and Lysinibacillus. Nearly one-third of inks labeled “sterile” contained microorganisms, and some detected bacteria have been linked to human infections.

Bacteria in the inks

Researchers retrospectively examined 259 unopened tattoo and permanent-makeup ink products collected in the United States over the past decade. Across four surveys, 35.4% of samples contained bacteria, with a 95% confidence interval of 21.6% to 49.1%. Contamination rates were about 33% for both tattoo and permanent-makeup inks.

Contamination was not significantly associated with the type of ink, a label claiming sterility or the product’s manufacturing origin. Bacillus species were isolated most often, followed by Pseudomonas, Staphylococcus and Lysinibacillus. Nearly one-third of products labeled “sterile” contained microorganisms. Some isolates, including Pseudomonas putida and Alcaligenes faecalis, are opportunistic pathogens with documented links to human infections.

The researchers’ network analysis connected inks, microbes and potential disease outcomes. Their analysis of the range of microbes across species suggested that further sampling could identify additional contaminants.

Why ink safety matters

Tattoo and permanent-makeup inks are injected directly into the dermis, so contamination can create a route for microorganisms to enter the body. The findings indicate that contamination was common across the tested products and was not limited to inks without a sterility claim. The researchers say the results support more sensitive detection methods, expanded surveillance and harmonized manufacturing standards for these products.

Evidence and caveats

This was a retrospective analysis of 259 unopened tattoo and permanent-makeup ink products collected in the United States over a decade and examined across four surveys. It shows that bacteria were detected in a substantial share of the tested products, but it does not establish that any particular ink caused an infection or measure infection rates among people. The abstract does not indicate whether the samples represent all products sold or describe the relative contribution of culture-based and molecular testing methods.

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