Triclosan, an ingredient in Colgate Total toothpaste, has reportedly been linked to cancer in mice.
The antibacterial chemical, which was banned from hand soaps in 2016, remains in toothpaste, according to The New York Times. The company reportedly convinced the Food and Drug Administration that its health benefits outweigh the potential risks.
Toothpastes with triclosan have been "demonstrated to be effective at reducing plaque and gingivitis," according to FDA spokeswoman Andrea Fischer. "Based on scientific evidence, the balance of benefit and risk is favorable for these products."
The only toothpaste in the U.S. containing triclosan is Colgate Total. Before the toothpaste was approved by the FDA in 1997, the agency asked the Colgate-Palmolive company to carry out toxicology studies on the chemical. After the studies, the FDA determined that the substance was safe.
Rolf Haden, an environmental security director at Arizona State University's Biodesign Institute, said that the decision to ban the ingredient in hand soaps but allow it to remain in toothpaste was puzzling.
"We put soap on our hands, and a small amount gets into our body," said Haden. He pointed out that when we put substances on our gums, "chemicals get rapidly absorbed into the bloodstream."
A study published in the Chemical Research in Toxicology journal found that triclosan could encourage the growth of cancer cells, reports Collective Evolution.
"Triclosan’s increasing detection in environmental samples and its increasingly broad use in consumer products may overcome its moderate benefit and present a very real risk of liver toxicity for people, as it does in mice," said San Diego School of Medicine Professor Robert Tukey, according to The Washington Post.
Another study in 2012 found that exposure to triclosan could weaken contractions of the heart and other muscles, according to Healthline.
Terry Collins, a Carnegie Mellon University green chemistry professor, said that he doesn't think the use of triclosan and similar chemical triclocarbon in consumer products is a good decision.
"I'm not in favor of banning these things," said Collins, "but the mass usage of them is almost certainly unwise."
Natural Resources Defense Council lawyer Mae Wu, who filed a lawsuit in 2010 which forced the FDA to make a decision on antibacterial soaps, said that consumers should look for alternatives to toothpaste with triclosan.
"It's aimed at preventing gingivitis, so if you’re at risk of that you might consider it," said Wu. "But for anyone else, it may do more harm than good."
Thomas DiPiazza, a spokesman for Colgate-Palmolive, said that the evidence is in the company's favor.
"The full weight of scientific evidence amassed over 25 years continues to support the safety and efficacy of Colgate Total," said DiPiazza.
Dentist Richard Niederman said that he isn't "an alarmist" about the use of triclosan in toothpaste.
"I would tell my patients if they are concerned about triclosan that stannous fluoride is also very effective for reducing plaque and gingivitis," said Niederman.