As winter flu season comes on, many of us in the Northwest start reaching for the anti-bacterial hand soap and similar products to kill the germs that spread the illness.
Now, research from the University of California Davis adds to a growing body of science that questions whether a key ingredient in hundreds of anti-bacterial products is safe.
If you washed your hands today with an anti-bacterial soap, the odds are good it contained a chemical called triclosan. Originally used as a pesticide, triclosan started being used in hospitals in the 1970s as a surgical scrub.
Over the past 30 years, it’s been put in a growing list of consumer products, from soap to deodorant to toothpaste. In fact, it’s in 75% of antibacterial hand soaps. You can also find it in kitchenware, clothes, even toys. That ubiquity concerns Bruce Hammock, a professor of entomology at UC Davis.
Bruce Hammock: “Triclosan worries me, because its use is very high, its use is growing and we do have this toxicity which at high levels could be serious if not fatal.”
Dr. Hammock is one of the scientists who conducted a study that found triclosan impairs muscle activity in animals. Hammock says there was a particularly dramatic effect on what’s called the “excitation-contraction coupling” in the heart.
Bruce Hammock: “This is basically how one heart cell talks to another heart cell to tell the heart to contract rhythmically.”
Hammock says mice given high doses of triclosan developed irregular heartbeat and died. Tests on muscle tissue in test tubes also showed impaired function after exposure to triclosan. Hammock concludes that the chemical’s wide, almost indiscriminate use in consumer products is unwise.
Bruce Hammock: “In hand soap, I personally see very little benefit, and I think for most people, the risk outweighs the benefit.”
Other research on triclosan has also raised questions about its impact. Dr. Susan Katz heads the Oregon chapter of Physicians for Social Responsibility. She says studies suggest triclosan is an endocrine disruptor, causing imbalances in the hormones that regulate the body’s immune response, leading to more severe allergic reactions.
Susan Katz: “Triclosan exaggerates their effect and makes the immune response greater to harmless allergens in the air.”
Katz also points to research showing triclosan could impact aquatic life in rivers and streams.
Susan Katz: “It goes into the wastewater system, but it’s only I think like 60 percent of it is degraded so a lot of it comes out intact into the water.”
The Centers for Disease Control and Prevention found three-quarters of Americans have traces of triclosan in their urine. Katz says the chemical’s wide use is a triumph of marketing over science.
Susan Katz: “There’s no evidence that it’s better than soap and water when you’re washing things up. There’s no evidence that cutting boards that you put it on have less problems with problem bacteria.”
In response to consumer concerns, a number of manufacturers have given up triclosan. Colgate Palmolive removed the chemical from most of its products in 2011. Proctor and Gamble and Johnson and Johnson have both pledged to phase it out over the next few years.
But Brian Sansoni says triclosan is getting a bad rap.
Brian Sansoni: “Triclosan is one of the most researched and reviewed and regulated ingredients in the consumer product sector.”
Sansoni is with the American Cleaning Institute, an industry group. He points out that no one has ever pinned any actual human harm to use of triclosan. The Food and Drug Administration first proposed regulating triclosan in 1978, but rules were never finalized.
That may change soon. The FDA recently settled a lawsuit by promising to propose regulations. Brian Sansoni says the industry welcomes the new proposal.
Brian Sansoni: “We certainly hope that it’s on the best science and the best data, related to how they may update the regulation.”
The proposed FDA rules are expected to be released next week. But whether they include new restrictions on use of triclosan or not, there’ll be a long process of public and industry input -- then further agency review -- before any regulations are finalized, likely in late 2016.