Packages of Colgate and Tom’s of Maine toothpaste on a store shelf in Portland. Joel Page/Associated Press, file

Tom’s of Maine is under fire from the U.S. Food and Drug Administration for using water contaminated with bacteria to manufacture toothpaste and clean equipment. An inspection also turned up a “black mold-like substance” at its Sanford manufacturing plant.

The FDA sent a warning letter to Colgate-Palmolive, the parent company of the Kennebunk-based toothpaste, body care products and deodorant manufacturer, outlining a slew of manufacturing violations.

The company has been aware since 2021 of potentially dangerous bacteria in water samples taken between then and 2022, according to a warning letter the FDA sent this month.

The FDA visited the Sanford site in May, when investigators also found the “black mold-like substance” and “powder residues” close to equipment that comes into contact with products.

Some contaminated water has been found in at least one batch of toothpaste and was used to clean manufacturing equipment, the FDA said. There was no investigation to assess how that impacted the product.

In another instance, the company found a small, “gram-negative” level of bacteria in its “Wicked Cool! Anticavity toothpaste,” the FDA said, but that was dismissed as contamination and the product was sold anyway.

Water samples included several bacteria – some in quantities “too numerous to count” – including Pseudomonas aeruginosa, which can cause blood and lung infections, according to the U.S. Centers for Disease Control and Prevention.

The company’s water system is inadequate, Francis Godwin, the director of the FDA’s Office of Manufacturing Quality, wrote in the Nov. 5 warning letter that the FDA recently shared online. “Water is a major ingredient in many of your (over-the-counter) drug products,” Godwin wrote. “It is essential that you employ a water system that is robustly designed and that you effectively control, maintain and monitor the system to ensure it consistently produces water suitable for pharmaceutical use.”

The toothpaste manufacturer’s response to the uncovered issues is also inadequate, he said.

“It does not include additional supporting evidence or testing results for the finished products.” Godwin also criticized their sampling methods.

The FDA had the company address its concerns in a response to the federal agency in June. But the FDA says it’s disappointed with what Tom’s and Colgate-Palmolive have submitted so far.

The company has been asked to submit a new, more thorough response, including a plan of correction. The FDA has urged them to work with a consultant.

In a statement, Tom’s of Maine said the company is working with the agency to remedy the issues and is in the midst of an ongoing “significant” upgrade to the Sanford plant’s water system.

“We have always tested finished goods before they leave our control, and we remain fully confident in the safety and quality of the toothpaste we make,” it said. “In addition, we have engaged water specialists to evaluate our systems at Sanford, have implemented additional safeguards to ensure compliance with FDA standards, and our water testing shows no issues.”

The company said it is committed to making safe and effective products, as well as maintaining trust in the Tom’s of Maine brand.

This is not the first time Tom’s of Maine has been under scrutiny by the FDA. In 2016, the company received citations for similar issues, including improper training for employees, unsanitary buildings and inadequate procedures to prevent product contamination, but the agency never went so far as to issue a warning.

Despite the reported quality issues, Godwin said Tom’s of Maine does not investigate all complaints, resulting in a strike for inadequate complaint procedure.

Only complaints related to adverse events, foreign matter and incorrect product are investigated. According to company policy, only complaints related to a “trend” trigger an investigation. The inadequate complaint procedure was another strike against the company.

Approximately 400 complaints related to odor, color and taste in toothpaste, including products for children, were ignored, Godwin said.

“Although you state complaint investigations were not required because there was no trend identified, you did not provide a documented evaluation determining the lack of trend for the quality issue specific to each complaint,” he said. “Instead, you included a general statement from the procedure in each of the complaint’s documentation.”

The FDA said that failing to address the violations could cause the agency to withhold approving new applications from the company, as well as withhold issuing export certificates.

Tom’s has 15 business days to respond to the warning with information about how it has addressed the violations and plans to prevent them in the future.

Staff Writer Emily Allen contributed to this report.