DISCLAIMER: I am not in support of or in protest of products containing or not containing these ingredients. These are compilation of scientific evidence based on the latest research findings.
Toxic? (PART TWO)
Hi Friends! This post is part two of the response to a post by a blog friend of mine, Small Footprints. I was supposed to post this on Sunday, but don't know why my internet connection was down for the past couple of days. Sorry about that! This post will be quite long too, so don't say I didn't warn 'ya :)
4. Sodium Lauryl Sulphate or Sulfate (SLS)
The "bad" name for SLS had been circulating on the internet since I finished high school, which wasn't THAT many years ago (10 years, to be exact) :) Is it really BAD, specifically in causing cancer? The answer is NO. My friends over in Snopes.com, a great website for checking various myths or rumors under the sun, had done an excellent "exposure" on the truth about SLS:
Sodium lauryl sulfate (also known as sodium laurel sulfate, or SLS) and its chemical relative, sodium laureth sulfate (i.e., sodium lauryl ether sulfate, or SLES), are substances used in products such as shampoo, toothpaste, and mouth rinses as foaming and cleansing agents, producing the lather and clean hair we all know and love. (SLS, because it is cheaper to produce, is more commonly used than SLES) SLS is an irritant, and a shampoo containing 15% SLS is mainly tolerable only because it comes in contact with the scalp for just a few minutes and is diluted with water while in use. Should you get some in your eyes you'd certainly want to flush it out as soon as possible, and you really don't want to swallow the stuff. Those are the greatest dangers SLS poses to the average consumer, however. FDA does require that fluoride toothpastes shipped as of 7 April 1998 carry a warning label about the dangers of swallowing too much toothpaste, and SLS is one of the three ingredients (along with sorbitol and fluoride) identified as posing a health risk. Because it causes cancer? No, because it can cause diarrhea.
SLS is even found in food products such as candy. For example, it's an ingredient in Candy Bubbles, described as "Bubbles you can eat!" Although the label warns that the product should not be eaten outright, Candy Bubbles are touted as a fat-free, calorie-free edible product. Hardly something the FDA would allow to remain on the market if one of its ingredients were known to cause cancer.
Additionally, all manufacturers of hazardous chemicals in the U.S. are required by the Occupational Safety and Health Administration (OSHA), a part of the U.S. Department of Labor, to file Material Safety Data Sheets (MSDS) for those products. An MSDS "contains written or printed material concerning a hazardous chemical as prescribed by law," including information "needed to insure the safety and health of the user at all stages of (the chemical's) manufacture, storage, use, and disposal." Examining the MSDS for sodium lauryl sulfate, we find that the "Health Hazard Data" section that SLS can produce some rather nasty side effects if you inhale or ingest it, get it in your eyes, or leave it in contact with your skin for too long. But we already knew all that, and the general results of this misuse are symptoms such as skin irritation or nausea, not cancer.
In fact, three different agencies - OSHA, the National Toxicology Program (NTP), and the International Agency for Research on Cancer (IARC) have all rated SLS as being non-carcinogenic.
How about the rest of this message? Should we be concerned because "the fact is that SLS is used to scrub garage floors, and it is very strong"? Not really. Detergent is detergent; the same properties that make a substance useful for cleaning your hair make it useful for cleaning your clothes or a garage floor. Obviously you wouldn't want to use the same strength of a substance such as SLS on your hair as you would on a garage floor, and that's why shampoos typically contain no more than a 15% SLS solution. Cinnamon oil is "very strong" too, and you'd burn your mouth if you swallowed it undiluted. That doesn't mean that lesser concentrations of cinnamon oil are harmful, though.
We're also warned that "research has shown that in the 1980's, the chance of getting cancer is one out of 8000 and now in the 1990's, the chances of getting cancer is one in three," as if the chances of contracting cancer had skyrocketed in the last few decades (with the implication that substances such as SLS are to blame for this rise). According to the American Cancer Society, the "probability that an individual, over the course of their lifetime, will develop cancer or die from it" was one in three for both men and women in the 1980s, and one in two for men and one in three in women in 1998. Hardly the alarming jump claimed. You might still think that one in three sounds awfully high, and that something must be causing all this cancer, something that didn't exist or wasn't in common use several decades ago, when far fewer people died or cancer. It's true that something causes cancer, but it's a fallacy to assume that this something wasn't around back in the days when fewer people died of cancer. A large part of the reason that so many people die of cancer these days is that they live much longer and don't die of something else first. Everybody dies of something, and since relatively few people these days die of smallpox or the plague or the measles or tuberculosis or polio or any of a number of other maladies we've cured or eliminated, they're around long enough to contract cancer. It's hardly alarming that people die of cancer in their seventies instead of dropping dead of heart attacks in their fifties.
So where does the idea that SLS is carcinogenic come from? Back in the 1970s some shampoos were found to be contaminated with small amounts of nitrosamines, which are carcinogenic. Ethanolamine lauryl sulfates used in these shampoos were determined to be the source of the nitrosamine contamination, and manufacturers took corrective action. Perhaps someone is now confusing ethanolamine lauryl sulfate with sodium lauryl sulfate. Or, since the "SLS is dangerous" message has been widely disseminated by sellers of "alternative" or "all natural" products who tout that their wares don't contain SLS, perhaps someone in the "natural products" business deliberately created the message as a way of drumming up sales. There's nothing like an unfounded medical scare to get those cash registers ringing, and you can altruistically claim you have your customers' best interests at heart while you fleece them.
Wherever this notion came from, there simply is no medical evidence that SLS poses a significant risk of cancer to consumers of household products such as shampoo and toothpaste.
Based on the HSDB, here are the evidence-based human health effects of SLS:
(i) Can produce allergic sensitivity reactions.
(ii) May produce drying effect on skin.
(iii) Commonest cause of eye irritation by commercial shampoos.
(iv) Among 242 patients suffering from eczematous dermatitis, the percentage of allergic reactions reached 54.6%. Great number of allergic reactions to SLS (6.4%) was observed.
(Blondeel et al., 1978) **PEER REVIEWED**
(v) Widely used anionic detergents of low acute & chronic toxicity.
(vi) Poison by intravernous and intraperitoneal routes. Moderately toxic by ingestion and a human skin irritant.
(vii) Minimum Fatal Dose Level:
PROBABLE ORAL LETHAL DOSE (HUMAN) 0.5-5 G/KG, BETWEEN 1 OZ & 1 PINT (OR 1 LB) FOR 70 KG PERSON (150 LB).
Based on the facts available, I don't think anyone should be afraid of using products containing SLS.
5. Sodium Laureth Sulfate (SLES)
The answer for this chemical is similar to the one above, since the chemical actions are the same as SLS.
The Cosmetic, Toiletry, and Fragrance Association (CTFA) and the American Cancer Society have stated that the common belief that SLES is a carcinogen is an urban legend or a myth, a view confirmed by toxicology research by the OSHA, NTP, and IARC. SLES and SLS, and subsequently the products containing them, have been found to contain parts-per-thousand to parts-per-million levels of 1,4-dioxane, with the recommendation that these levels be monitored. EPA considers 1,4-dioxane to be a probable human carcinogen, meaning that a daily consumption of one gram of 1,4-dioxane over a lifetime would increase the cancer risk by about one part in 3000. Such an intake would correspond to eating liters of "contaminated" SLES on a daily basis, which would be rather unhealthy because of the SLES itself, which is not used in products that are intended for oral ingestion. FDA encourages manufacturers to remove 1,4-dioxane, although it is not required by federal law.
So is there any concern about SLES, or SLS? Nopey nope nope.
6. Triclosan
BINGO!!! Why bingo? Because, of all 6 ingredients proposed to be "toxic", this is the one I could confirm to be BAD. Ladies and gentlemen, friends, PLEASE avoid using products containing triclosan.
Reports have suggested that triclosan can combine with chlorine in tap water to form chloroform gas, which EPA classifies as a probable human carcinogen. As a result, triclosan was the target of a UK cancer alert, even though the study showed that the amount of chloroform generated was less than amounts often present in chlorinated drinking waters.
Triclosan reacts with the free chlorine in tap water to also produce lesser amounts of other compounds, like 2,4-dichlorophenol. Most of these intermediates convert into dioxins upon exposure to UV radiation (from the sun or other sources). Although small amounts of dioxins are produced, there is a great deal of concern over this effect because some dioxins are extremely toxic and are very potent endocrine disruptors. They are also chemically very stable, so that they are eliminated from the body very slowly (they can bioaccumulate to dangerous levels), and they persist in the environment for a very long time.
A 2006 study concluded that low doses of triclosan act as an endocrine disruptor in the North American bullfrog. The hypothesis proposed is that triclosan blocks the metabolism of thyroid hormone, because it chemically mimics thyroid hormone, and binds to the hormone receptor sites, blocking them, so that normal hormones cannot be utilized. The negative effects of Triclosan on the environment and its questionable benefits in toothpastes has led to the Swedish Naturskyddsföreningen to recommend not using triclosan in toothpaste.
Triclosan is used in many common household products including Clearasil Daily Face Wash, Dentyl mouthwash, Dawn, the Colgate Total range, Crest Cavity Protection, Softsoap, Dial, Right Guard deodorant, Sensodyne Total Care, Old Spice and Mentadent.
At this time, in the United States, manufacturers of products containing triclosan must say so somewhere on the label.
STRIKE ONE:
In one study, recently accepted for publication in the journal Environmental Health Perspectives and made available online, Isaac Pessah, PhD, director of the U.C. Davis Children's Center for Environmental Health, looked at how triclosan may affect the brain. Pessah's test-tube study found that the chemical attached itself to special "receptor" molecules on the surface of cells. This raises calcium levels inside the cell. Cells overloaded with calcium get overexcited. In the brain, these overexcited cells may burn out neural circuits, which could lead to an imbalance that affects mental development. Some people may carry a mutated gene that makes it easier for triclosan to attach to their cells. That could make them more vulnerable to any effects triclosan may cause.
STRIKE TWO:
In another recent study this year, UC Davis researchers calls into question the widespread use of two active ingredients - triclocarban and triclosan - in personal hygiene products, including anti-bacterial bar and liquid soaps. Using human and animal cell lines, researchers found that triclocarban disrupts reproductive hormone activity and triclosan interferes a type of cell signaling that occurs in brain, heart and other cells.
"Americans spend nearly one billion dollars a year on these products even though recent studies show that they are no better than regular soap and water at reducing the spread of illness. Now we have added evidence that, in some cases, the benefits may not be worth the risks," said Dan Chang, professor emeritus of civil and environmental engineering.
"Manufacturers of products containing triclosan and triclocarban should consider providing cautionary labels. There are new health-related data on these chemicals that consumers should know about, even if the research is in its early stages," Chang said.
The current study was published online in Environmental Health Perspectives, a publication of the National Institute of Environmental Health Sciences, in May.
The authors of the study are part of the UC Davis Superfund Basic Research Program. The group, part of a national network, is charged with assessing and understanding the effects that exposure to environmental substances have on human health.
"We decided to take a look at triclocarban and triclosan because these compounds appeared to be building up in the environment," said Bruce Hammock, an Superfund Basic Research Program investigator and professor of entomology. The compounds are also increasingly being detected in human breast milk and urine, he said.
Triclosan and triclocarban were first introduced for use by surgeons and other operating room personnel to prevent bacterial infections. Today they are inexpensive and readily available, in part because the patents on them have expired. "We are not concerned about limited use in settings with clearly edvident high-value such as in surgical settings. It's the widespread use that is of concern," Hammock said.
Superfund researchers use bioassays to measure the kind of effects a substance might have on living organisms, using animal or human cell lines as proxies for human exposure. The four assays in this study looked at the effects of triclocarban and triclosan. One assay tests a second messenger system broadly used by cells in the peripheral and central nervous systems, a second examines another pathway important in protein synthesis and two assays evaluate the activity of male and female sex hormones (androgens and estrogens).
The first assay involved observing the impact of the chemicals on ryanodine receptors, proteins that serve to keep calcium levels in balance. Calcium is needed for proper cell signaling, especially in brain, heart and muscle cells where these receptors are found. Disrupting these levels could lead to alterations in cell function. Triclosan significantly increased resting calcium levels in the mouse cells used in the assay.
The second assay looked at the impact on aryl hydrocarbon receptors (AhR). Normally, this cell-surface receptor binds a protein that leads to changes in gene expression, the process by which information encoded in the DNA is translated into proteins. Binding of this receptor by the environmental toxin dioxin has been shown to cause everything from birth defects to tumor production. Triclosan exhibited weak activity in the AhR bioassay. Triclocarban exhibited no activity.
Because of feedback loops in the body, amplification of these hormones could have the effect of depressing natural estrogen and androgen production, potentially impacting fertility and other hormone-dependent processes. In the current study, besides carrying out the AhR assays, co-author Michael Denison repeated Lasley's experiments using a different human cell line. Denison, a professor of environmental toxicology, observed a similar amplification effect.
Chang said he feels strongly that consumers be provided information about potential hazards, though he is quick to point out that those who are not in high-risk groups may decide to continue their use of triclosan- and triclocarban-containing products. "I have not stopped using my gingivitis-fighting toothpaste. However, if I were a pregnant woman or the parent of a small child, I might check the labels of the products that I use and stop using any that contain those chemicals until we can work this out," Chang said.
And STRIKE THREE (AND Y'RE OUT!):
In a Dec 2007 study (please email me at tanj3@wyeth.com if you want the full paper), Aiello et al. concluded that the lack of an additional health benefit associated with the use of triclosan-containing consumer soaps over regular soap, coupled with laboratory data demonstrating a potential risk of selecting for drug resistance, warrants further evaluation by governmental regulators regarding antibacterial product claims and advertising. Further studies of this issue are encouraged.
So the overall conclusion for these two posts (PART ONE & TWO) is:
DEA, PP, Sodium hydroxymethylglycinate, SLS and SLES are SAFE to be used.
Triclosan MUST BE AVOIDED at all costs!
