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FDA rule removes triclosan and triclocarban from over-the-counter soaps, washes
ASU scientist has long studied the health, nature impacts of antimicrobials
September 2, 2016

For ASU scientist Rolf Halden, the ruling on over-the-counter soaps is an environmental and health victory a long time in the making

The U.S. Food and Drug Administration today issued a final rule establishing that over-the-counter consumer antiseptic wash products containing certain active ingredients can no longer be marketed.

Companies will no longer be able to market antibacterial washes with these ingredients because manufacturers did not demonstrate that the ingredients are both safe for long-term daily use and more effective than plain soap and water in preventing illness and the spread of certain infections. Some manufacturers have already started removing these ingredients from their products.

This final rule applies to consumer antiseptic wash products containing one or more of 19 specific active ingredients, including the most commonly used ingredients: triclosan (TCS) and triclocarban (TCC). These products are intended for use with water, and are rinsed off after use. This rule does not affect consumer hand “sanitizers” or wipes, or antibacterial products used in health-care settings.

Video: What consumers need to understand about antimicrobials.


“Consumers may think antibacterial washes are more effective at preventing the spread of germs, but we have no scientific evidence that they are any better than plain soap and water,” said Janet Woodcock, director of the FDA’s Center for Drug Evaluation and Research, in an FDA statement. “In fact, some data suggests that antibacterial ingredients may do more harm than good over the long-term.”

For ASU scientist Rolf Halden, the ruling has been an environmental and public health victory that was a long time in the making. 

"It is a public-health victory that will limit unnecessary and potentially harmful exposures in consumers who long have been misled about both risks and benefits of these antimicrobials,” says Halden, director of the Biodesign Center for Environmental Security at ASU's Biodesign Institute.

ASU Biodesign researcher
Rolf Halden

“Most people don’t use personal-care products correctly and are unaware of the legacy that they are leaving behind, which lasts decades or longer. The widespread use of antimicrobial compounds offers no measurable benefit for the average consumer yet creates a legacy pollution that can be traced back for half a century in the sediments of our drinking-water resources.”

Halden, a professor in ASU’s SchoolThe School of Sustainable Engineering and the Built Environment is part of the Ira A. Fulton Schools of Engineering. of Sustainable Engineering and the Built Environment, studies the broad interconnectedness of the water cycle and human health, with special emphasis on the role of man-made products and human lifestyle choices on environmental quality. It has increasingly led him on a journey from scientific discovery to reforming public policy on the antibacterial soap issue.

Halden’s team was the first to find significant concentrations of TCC and TCS dating back to the 1950s in sediments of New York’s Jamaica Bay and Baltimore’s Chesapeake Bay, where they were discharged in treated domestic wastewater.  More recently, Halden found the same antimicrobial ingredients contaminating Minnesota’s freshwater lakes, released into nearby waters from various human activities.

Halden’s team found the antimicrobials in wastewater treatment plants of over 160 U.S. cities, showing that half to three quarters of the chemicals did not degrade and persisted in sewage sludge. The problem with these substances is that their chemical structure is mostly foreign to nature. This leaves natural breakdown mechanisms and enzymes ineffective in destroying them.

“In the built environment, it is us, the creators and inhabitants, who store the non-green, recalcitrant chemistry in our bodies, mostly in adipose tissue, and in women also in breast milk,” Halden said.

Antimicrobials have been detected in human blood and urine. The compound TCS was even found in 97 percent breast milk samples, placing an unnecessary risk on newborns’ health.

TCS and TCC are known endocrine disruptors. These mimic hormones found in people and wildlife, with potential adverse impacts on sexual and neurological development. In collaboration with Laura Geer from the State University of New York, Halden and his team found various antimicrobials in newborns in Brooklyn and observed decreased gestational age at delivery in mothers exposed to TCC.

Geer said the study also yielded a link between women with higher levels of butylparaben, an antimicrobial commonly used in cosmetics, and shorter newborn lengths. The long-term consequences of this are not clear, but Geer adds that if this finding is confirmed in larger studies, it could mean that widespread exposure to these compounds will cause a subtle but large-scale shift in birth sizes.

The Minnesota legislature was so alarmed by these and other researchers’ findings that it instituted the first ban of problematic antimicrobials from all state agencies. Some companies, such as Johnson & Johnson and Procter & Gamble, have announced that they are phasing out the compounds from some products.

Timeline of regulatory actions regarding antimicrobials
Prior to the landmark FDA ruling, there has been a long history of usage and regulatory actions concerning antimicrobials in personal-care products.


Halden knows that monitoring alone will not quell the rising tide of emerging contaminants. Regulation holds the key to truly effecting change. In February 2011, Halden participated in a congressional briefing panel in Washington, D.C., about the public health dangers of TCC and TCS.

The FDA issued a proposed rule in 2013 after some data suggested that long-term exposure to certain active ingredients used in antibacterial products — for example, triclosan (liquid soaps) and triclocarban (bar soaps) — could pose health risks, such as bacterial resistance or hormonal effects. Under the proposed rule, manufacturers were required to provide the agency with additional data on the safety and effectiveness of certain ingredients used in over-the-counter consumer antibacterial washes if they wanted to continue marketing antibacterial products containing those ingredients. This included data from clinical studies demonstrating that these products were superior to non-antibacterial washes in preventing human illness or reducing infection.

Antibacterial hand and body wash manufacturers did not provide the necessary data to establish safety and effectiveness for the 19 active ingredients addressed in this final rulemaking. For these ingredients, either no additional data were submitted or the data and information that were submitted were not sufficient for the agency to find that these ingredients are Generally Recognized as Safe and Effective (GRAS/GRAE). In response to comments submitted by industry, the FDA has deferred rulemaking for one year on three additional ingredients used in consumer wash products – benzalkonium chloride, benzethonium chloride and chloroxylenol (PCMX) – to allow for the development and submission of new safety and effectiveness data for these ingredients. Consumer antibacterial washes containing these specific ingredients may be marketed during this time while data are being collected.

Washing with plain soap and running water remains one of the most important steps consumers can take to avoid getting sick and to prevent spreading germs to others. If soap and water are not available and a consumer uses hand sanitizer instead, the U.S. Centers for Disease Control and Prevention recommends that it be an alcohol-based hand sanitizer that contains at least 60 percent alcohol.

Since the FDA’s proposed rulemaking in 2013, manufacturers already started phasing out the use of certain active ingredients in antibacterial washes, including triclosan and triclocarban. Manufacturers will have one year to comply with the rulemaking by removing products from the market or reformulating (removing antibacterial active ingredients) these products.

The Center for Environmental Security is one of 15 centers in ASU’s Biodesign Institute and is jointly supported by ASU’s Global Security Initiative.



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Global-warming data not enough to predict animal extinction

How shade is distributed affects lizards' ability to regulate body temperature.
Nearly 40 percent of the world's lizards are expected to become extinct by 2080.
September 5, 2016

Study co-authored by ASU professor shows that how shade is distributed throughout an animal’s habitat plays a role in well-being

Current models used to predict the survival of species in a warming world might be off target, according to new research that enlisted the help of dozens of spiny lizards in the New Mexico desert.

Nearly 40 percent of the world’s populations of lizards are expected to become extinct by 2080, because the Earth is warming faster than these populations can adapt.

But a new study, published today in Proceedings of the National Academy of Science, shows that to make accurate predictions, study models must include much more data about how shade is distributed throughout an animal’s habitat.

“The real fear is that previous research has underestimated the risk of extinction,” said Mike Angilletta, a professor at Arizona State University’s School of Life Sciences and co-author of the study.

“Most models assume that an animal can be anywhere in its environment at any time, which doesn’t account for how much energy an animal spends to regulate its temperature. Animals have to move and search for shade, which makes cooling down more difficult when patches of shade are far apart,” Angilletta said.

“This is a breakthrough paper,” according to Raymond Huey, a professor emeritus of biology at the University of Washington. “Scientists studying climate warming will now be forced to evaluate the spatial distribution of sunny-shady patches, and not just compute the fraction of an area that is sunny or shady. Frankly, that makes our research lives much harder, but also much more interesting.”

Shade structures in the desert

The researchers set up
shade structures in the
New Mexico desert to
study how well a lizard
can regulate its

Photo by Matt Schuler

Even a small change in body temperature can dramatically affect an organism’s well-being, like when a person’s temperature rises 1 or 2 degrees. Reptiles, including lizards, regulate their body temperatures by moving between warm and cool areas within their home ranges.

It isn’t just the relative proportion of warm and cool areas that affects how well a lizard can regulate its temperatures, Huey said, but also how they are distributed in space.

The spiny lizards in the study regulated their temperatures much more efficiently when they had many small patches of shade, which they could easily reach to cool off, instead one large clump of shade in a wide-open space. 

“Depending on the complexity of the environment, previous estimates of extinction may be too high or they might not be high enough,” said Mike Sears, an associate professor of biology at Clemson University and lead author of the study.

Sears has spent 20 years studying lizards. He says the reptiles are especially suited for climate-change studies because “they’re like little thermostats running around.”

What makes this study remarkable, Huey said, is that it tackles three issues at once.

“It develops original and highly sophisticated computer simulations of animal movement patterns in complex thermal environments,” Huey said. “It adds large-scale experiments of real animal movement patterns in the field. Finally, it shows that climate warming, in realistic thermal landscapes, may have more serious effects than predicted so far.”

When Sears first questioned the current models, he built a computer simulation to test their assumptions. Digital lizards followed algorithms that regulated body temperatures most efficiently. In the virtual environment, Sears’ digital lizards told him how much energy they spent on regulating their body temperatures when shade was either clumped together or spaced apart.

When shade was dispersed throughout a simulated environment, the digital lizards were able to regulate their temperatures more efficiently: They required less energy to move from patch to patch. When shade was isolated to one location, the lizards had to move farther away to hunt for food, which required more energy.

Angilletta, Sears and colleagues from two other universities tested their computer model with real lizards near the University of New Mexico’s Sevilleta Field Station.

The researchers fenced in nine arenas, each 20 by 20 meters square. To mimic the shade of the simulations, they stretched equal areas of shade cloth over each arena, but arranged the cloth differently—one big clump of shade, four medium-sized patches of shade or 16 small patches.

Shade structures in the desert
It isn’t just the relative proportion of warm and cool areas that affects how well a lizard can regulate its temperatures, the researchers said, but also how they are distributed in space. The spiny lizards in the study regulated their temperatures much more efficiently when they had many small patches of shade, which they could easily reach to cool off, instead one large clump of shade in a wide-open space (seen from above). Photo by Matt Schuler


Each group of lizards spent two days in each environment, and their body temperatures were monitored through tiny, surgically implanted sensors.

When the lizards were in the arena with one large clump of shade, their temperatures varied 12 percent more than when they were in the arena with four patches of shade, and 10 percent more than when they were in the arena with 16 patches of shade. Thus, more patches mean more careful thermoregulation.

The results corresponded to Sears’ computer model. In the simulations, digital lizards experienced 9 percent more variation in body temperature when shade was provided in one clump compared with either four patches or 16 patches.

Huey likened the lizards’ behavior to running across a hot, sandy beach in bare feet to get from a parked car to the cool sands by the ocean.

“As a young lad, I leaned that spatial distribution of thermal resources mattered,” Huey said. “But Sears and colleagues take this theme to a general and sophisticated new level, and show how the distribution of shade patches affects the ability of lizards to use behavior to regulate their body temperatures, and also why an understanding of that distribution will be critical to predicting biological responses to climate warming.”

The research confirmed Sears’ hunch, that global temperatures aren’t sufficient for predicting how well species survive.

“If we really want to understand how populations of organisms will respond to climate change, we can't use a simple, back-of-the-envelope method,” Sears said. “We need to think on a finer scale than we have been.”

Top photo by Agus Camacho

Sandra Leander

Manager, Media Relations and Marketing, School of Life Sciences