Sodium
Laureth Sulfate - Download
PDf copy
There has been much concern recently concerning SLS. The e-mail (bottom
of article) has been circulating since at least 1998 SLS or Sodium
Lauryl Sulfate, and Sodium Laureth Sulfate (properly abbreviated SLES)
are commonly used products in tooth pastes and shampoos. They are primarily
used for creating a foaming action. They are only needed in very small
amounts, and they have been used for years without any health concerns.
There are no studies (that are worth the paper they are written on)
I can find that link either of these chemicals to cancer. Numerous
sites across the Internet have labelled this email letter a hoax.
Unlike fluoride, which has hazards
that are, very well documented SLES and SLS which are not the same
but cited as such by the hoax is without doubt a hoax. However
it is worth noting that Sodium lauryl sulfate is well known to
be a skin and eye irritant and can cause dermatitis with prolonged
contact in high concentrations. Results of some tests on animal
tissues indicate that it's mutagenic - i.e., it may be related
to abnormal cell mutations - though the evidence is inconclusive.
Even so, scientists familiar with the substance insist it is not
dangerous in the concentrations found in personal care products.
This is based as mentioned above
on high concentrations the fact remains that to pick one product
out the actual amount is between 0.04% and 0.07% not very high (Green
Things). The manufacturer mentioned that they use it in their creams
as a binding agent, and would prefer not to use it but the cream
'just falls apart' without it.
Daily Bread would prefer not to
have any product, which contains chemicals such as SLS or SLES. We
do not believe a hoax such as this even if it of some concern to
people on the use of any chemicals is the right way. The stories
are misinformation, which is wrong. Its worth noting that some other
ingredients may be more of an hazard some of these may be in fact
be natural ingredients! But that's another subject.
Therefore at Daily Bread you will
find some products that do contain it, Kingfisher toothpaste being
one. The Ecologist magazine states the hazards with this substance
but yet recommends Kingfisher as one of the better toothpastes.
One manufacturer of products that we stock mentions that it contains
NO SLES on the label. However the same manufacturer admits that it
is a marketing ploy, as they themselves believe that there is nothing
wrong with it!
We at Daily Bread are actively
seeking as many products as we can that contain only natural ingredients.
Here is a FAQ on the subject.
* Q: Is sodium laureth sulfate commonly found in shampoos and toothpastes?
A: Shampoos, frequently; toothpastes, occasionally. (It's much more
common to find the harsher surfactant sodium lauryl sulfate in toothpastes.)
* Q: Is sodium laureth sulfate known to cause cancer?
A: No. The chemical does not appear on any official list of known
or suspected carcinogens.
* Q: Is sodium laureth sulfate properly abbreviated as "SLS?"
A: No. The correct abbreviation is "SLES." The chain letter confuses
this compound with another: sodium lauryl sulfate, which is abbreviated "SLS." The
two substances are related, but not the same.
* Q: Is sodium laureth sulfate used to scrub garage floors?
A: No.
* Q: What about the other one - sodium lauryl sulfate - is it used
to scrub garage floors?
A: No doubt! SLS is a powerful surfactant (wetting agent) and detergent.
It is used in both industrial cleaning products and, in lesser concentrations,
personal care products.
* Q: Is sodium lauryl sulfate commonly found in shampoos and toothpastes?
A: Yes, both. It's also found in shaving creams and other lathering
products.
* Q: Ah. Well, then, is SLS a known carcinogen?
A: No, it is not on any official list of known or suspected carcinogens.
But it is a harsher chemical than SLES, which is why SLES is typically
used in baby shampoos instead. Sodium lauryl sulfate is well known
to be a skin and eye irritant and can cause dermatitis with prolonged
contact in high concentrations. Results of some tests on animal tissues
indicate that it's mutagenic - i.e., it may be related to abnormal
cell mutations - though the evidence is inconclusive. Even so, scientists
familiar with the substance insist it is not dangerous in the concentrations
found in personal care products.
* Q: Would a manufacturer freely admit to consumers, as claimed in
the message, that it knowingly uses a carcinogen in its products "because
we need that substance to produce foam?"
A: Of course not.
* Q: Is it true that my chances of getting cancer are "1 out of 3" in
the '90s?
A: Yes, with a few qualifications. The problem with stating probabilities
in this case is that there's no way to generalize accurately. The
reasons are: 1) cancer risks for individuals vary according to a
host of factors, including gender, race, habits, and family history;
and 2) the likelihood of any individual contracting cancer is also
a function of their age. For example, if you're 20 years old, the
odds are much greater that you'll contract cancer in your lifetime
than they are if you're 50, simply because there's a longer time
span involved.
That said, the longer answer is: For an "average person" (that is,
someone of no particular age or gender who lives nowhere in particular
and inherited no genes from his or her parents), the chances of getting
cancer over a lifetime work out to somewhere between 1 in 3 and 1
in 2, at present.
* Q: Were the chances of getting cancer in the 1980s "1 out of 8,000?"
A: No, that's absurd. Cancer rates were approximately the same two
decades ago as they are now; if anything, they were a bit higher.
* Q: Really? Aren't cancer rates rising?
A: No, in the United States they have been falling, though at a fractional
rate and there's no telling if that trend will continue.
* Q: Is cancer a "virus," as alleged in the email?
A: No.
* Q: Is the chain letter a hoax?
A: Most likely. At the very least, it contains egregiously inaccurate
information. But we can only guess at the motives of whoever launched
it.
* Q: Where did the misinformation come from?
A: Well, if you're asking who started the chain letter, there's no
way of knowing. As to the misinformation itself, it turns out that
there are a good many Web pages containing very similar - and in
some cases identical - statements. It's a good bet that it all came
from the same source at some point in time.
Interestingly, all these Websites are maintained by "independent
distributors" for multi-level marketing companies hawking "natural" personal
care products, etc. As a matter of fact, the majority of URLs returned
in a standard Web search on the keywords "sodium laureth sulfate" point
to versions of the same propaganda. Assuming all this information
did come from the same source, the author of our chain letter and
some of these Web entrepreneurs are sloppy copyists at the very least,
and/or intent on slanting the "facts" to suit their purposes.
In the chain letter, for example, the cancer rate in the 1980s is
alleged to be "1 out of 8,000"; the Web pages tend to say that was
the cancer rate in 1901. That sounds more reasonable, but it's no
cause to assume the Websites are entirely accurate. On some of them,
the ratio cited for 1901 is not "1 out of 8,000," but "1 out of 80." Again,
some of these authors are either making it up as they go along, or
copying the information very carelessly.
Misinformation has a way of multiplying.
Many of the pages I looked at were
littered with inaccuracies, deceptive statements and outright lies.
One even alleges that "In 1993 it was documented that sodium lauryl
sulfate (SLS) and sodium laureth sulfate (SLES) were the leading
cause of blindness in children" - as if claiming they're carcinogens
weren't inaccurate enough. Another page links prominently to a site
vending quack cancer cures. In some cases, the texts cite legitimate
medical studies, but in a misleading way, making it appear as if
the studies prove much more than they actually did. Another site
provided links to back up their claims but oddly the links were to
pages that stated that there was not much wrong with SLS or SLES.
Small wonder that by the time this
information made its way into chain letter form, virtually every
statement in it was outrageously false.
What's worse, as the chain letter
circulates, the information continues to degrade. One of the more
recent variants of the email gives the abbreviation of sodium laureth
sulfate as "SLY," which is doubly wrong.
* Q: Do you think the chain letter may have been deliberately started
to frighten people into using other products?
A: I suspect it, but there's no way to know for sure, and I can't
prove it. For all we know, someone came across this stuff by accident,
innocently believed it to be true, and decided to share it with others.
* Q: Do you really think that was the case?
A: I doubt it.
* Postscript: The old adage, "Where there's smoke, there's fire," may
apply here. While the "facts" stated in the sodium laureth sulfate
warning are almost entirely false, there may be other potentially
hazardous substances in name-brand personal care products
Tech stuff
'Sodium dodecyl sulfate' ( SDS or NaDS) ( C H3(CH2)11 O SO3 Na) (FW
288.38), also known as 'sodium lauryl sulfate' ( SLS), is an ionic
detergent that is used in household products such as toothpastes,
shampoos, shaving foams and bubble baths for its thickening effect
and its ability to create a lather. The molecule has a tail of
12 carbon atoms, attached to a sulfate group, giving the molecule
the amphiphilic properties required of a detergent.
It is prepared by sulphation of lauryl alcohol (1-dodecanol, dodecyl
alcohol, CH3(CH2)10CH2OH) followed by neutralisation with sodium
carbonate. It is used in both industrially produced and home-made
cosmetics.
Like all detergents (as opposed
to true soaps), it removes natural oils from the skin, and can therefore
cause skin irritation. It is particularly irritating to the eyes.
SLS can be converted by ethoxylation
to sodium laureth sulphate (also called sodium lauryl ether sulphate;
SLES), which is less harsh on the skin.
In laboratories, SDS is commonly
used in gel electrophoresis ( SDS-PAGE), where its detergent properties
help keep the proteins being studied in a denatured state.
The critical micelle concentration in pure water is 0.0085 M, and
the aggregation number at this concentration is around 50.
Copy of 2 emails one of which may not be the original hoax but is
close the other a reply.
The original message is shown first, the rebuttal follows:
-----Original Message-----
From: Wendy S. Lin
To: Max Yue Zhang
Date: Tuesday, September 15, 1998 2:06 AM
Subject: Health concern
Just for your info, and please take note of the shampoo you use to
wash your hair every night! Girls will definitely use more! Check
the ingredients listed on your shampoo bottle, and see if they have
this substance by the name of Sodium Laureth Sulfate, or simply SLS.
This substance is found in most shampoos, and the manufactures use
it because it produces a lot of foam and it is cheap. BUT the fact
is that SLS is used to scrub garage floors, and it is very strong.
It is also proven that it can cause cancer in the long run, and this
is no joke.
I went home and checked my shampoo (Vidal Sasoon), it doesn't contain
it; however, others such as Vo5, Palmolive, Paul Mitchell, the new
Hemp shampoo, etc.. contains this substance. So I called one company,
and I told them their product contains a substance that will cause
people to have cancer. They said "Yeah, we knew about it but there
is nothing we can do about it because we need that substance to produce
foam. By the way Colgate toothpaste also contains the same substance
to produce the "bubbles". They said they are going to send me some
information.
Research has shown that in the 1980s, the chance of getting cancer
is 1 out of 8000 and now, in the 1990s, the chances of getting cancer
is 1 out of 3, which is very serious. So I hope that you will take
this seriously and pass this on to all the people you know, and hopefully,
we can stop "giving" ourselves the cancer virus. This is serious,
after you have read this, pass it on to as many people as possible,
this is not a chain letter, but it concerns our health.
Michelle Hailey
Executive Secretary
University of Pennsylvania Health System
Office of Legal Affairs
(215) 662-2546
------------------------------
From: Chan, Lillian [mailto:lchan@utmb.edu]
Sent: Wednesday, September 16, 1998 11:55 AM
Everyone,
One annoying (but potentially dangerous) feature of e-mail is that
all sorts of misinformation gets passed around. This reflects the
gulliblility of the general public.
After receiving this email, I called Michelle Hailey at UPenn (her
name and contact information was at the bottom of the message) to
try to find out her source of information on SLS. She has no idea--she
was just passing along an email she got from someone else and unfortunately
for her, her name got attached to it. She deserves the hassle she
is getting for sending out this email (she's been getting numerous
phone calls), but whoever originated it should really be the person
taken to task.
The compound mentioned in the e-mail below is sodium lauryl sulfate.
Another name for it is sodium dodecyl sulfate or SDS. It is a detergent
and is used in all kinds of household goods, (including shampoos
for hair as well as for carpets). We use it in the laboratory all
the time for solubilizing proteins.
There is NO documented evidence that SDS is carcinogenic. If inhaled
(in powder form), it can cause irritation to the mucous membranes.
Some of you may have experienced stuffy sinuses when you go into
places that have old carpets (for example, motels) that have been
shampooed multiple times. That may have been caused by the residual
SDS left behind by the carpet cleaning solution. Of course excess
amounts of anything, either inhaled or ingested, can cause harm to
your health -- even table salt can be harmful.
I strongly urge all of you to be careful and discerning about what
you read. Unless solid evidence from reputable (and verifiable) sources
are provided, don't believe everything that is in print. Also, please
don't pass on anything that you don't know is true. There are just
too many alarmists out there already.
Lillian
-----------------
Above article compiled by John
Clarke - Daily Bread Northampton |
