http://www.oregonlive.com/living/oregonian/index.ssf?/base/living/121909290381270.xml&coll=7&thispage=1
Wednesday, August 20, 2008
CARRIE NUGENT
The Oregonian Staff
Dish soap. Conveyor belts. Toothpaste. Socks. Deodorant. Latex paint.
You can buy “antibacterial” versions of plenty of products, all imbued with triclosan, the chemical that provides the bacteria-killing muscle. Classified as a pesticide, triclosan kills good and bad bacteria indiscriminately. That’s just one of several concerns and controversies surrounding the man-made chemical:
It lingers in the environment.
Shoppers might not know when they’ve bought antibacterial products because it’s not always clear what is or isn’t.
What does it mean that it’s in so many household products?
Studies show that for household needs, regular soap and water fight bacteria just fine, so why use it?
Manufacturers maintain it is innocuous — unless you are bacteria. Opponents worry about its health effects and that widespread use will breed resistant bacteria.
Triclosan, initially intended for medical settings, isn’t the only antibacterial chemical — its cousin, triclocarban, also is used sometimes. Of course, not all products have these chemicals added.
To help shoppers choose more wisely, we sort out what’s known.
CLAIM: Antibacterial soaps get things cleaner
The concentrations of triclosan in soaps have not been found to be any more effective than plain soap and water.
A study comparing households with and without triclosan products found no difference in cleanliness. Killing all bacteria, as triclosan does, can harm health. It kills not only the “bad” bacteria that can make us sick — such as E. coli — but also the harmless or even helpful bacteria hanging around our body that we need.
“Washing with soap and water is probably better than putting something on you that is over the long term inhibiting bacteria growth,” says Fred Berman, director of the Center for Research on Occupational and Environmental Toxics at Oregon Health & Science University.
“To go beyond that, in a way, is overkill. We don’t know for sure whether the use of something like triclosan is ultimately harmful.” Bottom line: Plain soap and water is all you need to keep your hands and dishes clean. Check “active ingredients” on the back label to see if soap contains triclosan.
CLAIM: It does no harm
Triclosan attacks bacteria differently than alcohol or soap and water. Some scientists are concerned that casual use of the chemical could breed triclosan-resistant bacteria, robbing people with weak immune systems of an important protection.
Laboratory cultures of E. coli bacteria can develop resistance to triclosan-treated soaps. Many strains of E. coli are harmless, but a few can cause severe food poisoning, such as the strains behind several meat and vegetable recalls this summer.
Other bacteria, studies show, aren’t as adaptable, but some scientists think that in time, triclosan-resistant strains of all kinds of bacteria will emerge. Bottom line: Limit triclosan to medical settings to prolong its effectiveness.
CLAIM: Triclosan keeps kids healthier
Many advertisements target parents, showing mothers wiping pools of chicken juice on counters or adorable toddlers sneezing on toys.
Several commercials have been downright misleading. (The Environmental Protection Agency forced Microban in 2004 to back off its marketing claims.) According to Dale Kemery of the EPA, the agency regulates triclosan as a bacteriostat — it stops bacteria from reproducing but does not kill them. Any further implication, such as that a treated plastic toy will keep your kid from catching his buddy’s strep throat, go beyond what triclosan has been proved to accomplish.
Besides, some bacteria build healthier immune systems. A widely cited study shows that in a rural community, children who grew up on farms had fewer allergies than those who did not. The hypothesis is that immune systems need a certain level of bacteria to develop. Bottom line: “I think there is something to the argument that we are trying to be too sanitary,” OHSU’s Berman says. “I’m not aware, in the literature or anywhere, of children having increased illness because they are playing with toys. And if parents are concerned — they can just wash the toys in mild soapy water occasionally.”
CLAIM: It’s rigorously tested
Two government agencies regulate triclosan — the Food and Drug Administration for products like soap and toothpaste, the EPA for products like mattresses and plastic toys.
The EPA is reviewing triclosan, along with other chemicals under the Federal Insecticide, Fungicide and Rodenticide Act, to ensure that they meet standards. To read the preliminary assessment online: epa.gov/oppsrrd1/REDs/factsheets/triclosan_fs.htm
Like with many government reports, not everyone was pleased with the results. The assessment states, “There are no food-use tolerances for triclosan. Therefore, a formal Food Quality Protection Act analysis is not needed for this chemical.”
Some see that as a problem because triclosan is often in dishwashing soap. And unlike conventional soap, triclosan does not easily rinse away — the molecule’s slow solubility allows it to stick around — on your plates, on your silverware and on your hands. That’s why some people want the EPA to evaluate triclosan and food-use tolerance. The EPA did evaluate the risk of it entering food that touches countertops, cutting boards and the like, and said: “All results are below level of concern.”
Products marketed as dishwashing liquid are labeled “antibacterial hand soap” if they include triclosan, says Jay Feldman, executive director of Beyond Pesticides, based in Washington, D.C. That allows triclosan products an easier path to federal approval.
“Many people wash their fruits and vegetables with this soap, not giving it a second thought that this product contains this extra chemical, that in this case has not been evaluated to use on food,” Feldman says. Bottom line: The EPA’s final decision on triclosan is scheduled for September.
CLAIM: It disappears down the drain
Wastewater treatment removes triclosan in varying efficiencies, between 53 and 99 percent, according to the EPA. What’s left ends up in the environment, generally sticking to sediment.
It’s found at low levels in streams throughout the world as well as in our own backyard, including Fanno Creek, the Columbia Slough and the Tualatin River. It’s not clear how or whether plants and animals are affected by constant low levels. However, the EPA’s preliminary assessment concludes, “Triclosan is highly toxic to freshwater invertebrates.”
Other troubling findings: University of Minnesota researchers have shown sunlight can convert triclosan to a toxin. Scientists at Virginia Tech discovered that triclosan mixed with chlorinated tap water — like what happens when you wash dishes or shower — can form chloroform, a carcinogen.
Triclosan’s chemical structure resembles the thyroid hormone. A study at the University of Victoria in Canada showed triclosan affected tadpole development, though a later study, funded by triclosan manufacturer Ciba, indicates that low levels do not affect tadpoles.
Triclosan can be absorbed through skin. The Centers for Disease Control and Prevention have found widespread exposure in the United States. One study found it in some human breast milk. Bottom line: Triclosan is in the environment and our bodies — and scientists aren’t sure of the consequences.
To kill bacteria without triclosan:
Ordinary soap and water
Diluted solution of bleach and water
Alcohol
Hydrogen peroxide
Products with triclosan
Not everything has triclosan. Check “active ingredients” on the back label of items including soaps, toothpaste and deodorant, which must list it.
Some, but not all, Microban products contain triclosan. However, unlike FDA-regulated products like dish soap, manufacturers are not required to list triclosan as an ingredient.
The list of products is from an EPA report on triclosan. Not all brands and versions of these items contain triclosan: plastic toys, floors, brooms, caulking compounds, latex paints, shower curtains, tents, mattresses, toothbrushes, toilet bowls, garbage cans, insulation, air filter materials, upholstery fabrics, rugs/carpets, conveyor belts and ice-making equipment.