Sodium Laureth Sulfate, Sodium Lauryl Sulfate
There is a lot of information – and misinformation – in the media about
these surfactants. Several internet websites, particularly those concerned
with human health and environmental safety, list all of the reasons their
products do not contain SLS or SLES. Other sites, such as "urban legends"
sites, and specifically those sites that advertise products containing SLS
or SLES, claim that all of the information showing SLS and/or SLES to be at
least worth further study, if not downright dangerous, is nothing but hype.
SLS/SLES is a detergent, wetting agent, and emulsifier. It is used in about
98% of all "personal care" products as well as other products; hand and
body creams, depilatories, bubble baths, hair color kits, shampoos,
conditioners, toothpastes, shaving cream, shower gel, facial cleansers,
"baby wipes", "soapless" shampoos, and many others.
It is sometimes listed as "coconut oil" or "from coconuts" because it is
originally derived from coconuts. However, pure, unprocessed coconut oil is
NOT SLS. The American College of Toxicology says that SLS stays in the body
up to five days. Other studies show it easily penetrates the skin, and
enters and maintains residual levels in the heart, liver, lungs, and even
the brain. X6
Cosmetics-industry apologists often claim that the same American College of
Toxicology study also reports: "Both Sodium and Ammonium Lauryl Sulfate
appear to be safe in formulations designed for discontinuous, brief use
followed by thorough rinsing from the surface of the skin. In products
intended for prolonged contact with skin, concentrations should not exceed 1%."
Well, yes, it does say that. Please notice the words "discontinuous, brief
use followed by thorough rinsing…." – how many of America’s children have a
"discontinuous, brief" bubble bath? And "should not exceed 1%" – yet, in a
number of shampoos, SLS is the FIRST ingredient listed. It definitely
comprises more than 1% in those products.
In addition, since it is in nearly every product used for personal
cleaning, any one person taking a shower, shampooing and conditioning hair,
using a special cleanser for "sensitive" skin, and brushing teeth, has just
absorbed far more than the supposed "safe" amount.
Worse, now some toothpastes containing both SLS and Triclosan are claiming
that their toothpastes "continue working" or "stay on the teeth" for up to
twelve hours after brushing. That is hardly a "discontinuous, brief use".
Here is a synopsis of what some reports show about Sodium Lauryl and
Laureth Sulfate:
SLS penetrates eyes and tissues. Tests show that SLS can penetrate into the
eyes as well as systemic tissues (brain, heart, liver, etc.) and shows
long-term retention is those tissues. There is an immediate concern
relating to this eye penetration, especially when used in soaps, shampoos,
and bubble baths: Dr. Keith Green, Ph.D., D.Sc., reports that…."Sodium
Lauryl Sulfate denatures the proteins of eye tissues, impairing development
permanently. Because it is absorbed through the skin, it does not have to
enter the eye directly….", And "Sodium Lauryl Sulfate impairs proper
structural formation of young eyes and causes permanent eye damage. SLS
causes eye irritation, is linked to cataracts, and delays healing of
corneal tissue….".x8
SLS can form nitrates and nitrosamines (potent carcinogens that cause the
body to absorb nitrates at higher levels than even nitrate-contaminated
food, such as some hot dog meats or some bacon). Particularly in
combination with the DEA, TEA, and MEA (Diethanolamine, Triethanolamine,
and Monoethano- lamine, themselves very questionable ingredients) SLS/SLES
has been found capable of producing these carcinogens. The FDA is currently
studying the problem of the Di-, Mono-, and Tri- ethanolamines and is
considering legal options at this time.
SLS/SLES can strip moisture and oils from the skin. It is a degreaser as
well as a sudsing agent. According to the Journal of Investigative
Dermatology, and the above-mentioned J. Am. College of Toxicology report,
SLS produces skin and hair damage, including cracking and severe
inflammation of the derma-epidermis tissue. The denaturation properties can
also separate and inflame skin layers. SLS has a "degenerative effect on
the cell membranes" and SLS causes slight to moderate skin irritation in
low concentrations, and skin corrosion and severe irritation in high
concentrations.x9
SLS/SLES may not "cause" cancer, but definitely can produce carcinogens in
combination with other common ingredients. That alone should be enough to
initiate further studies. And the questions regarding eye damage,
particularly to babies and children, are certainly deserving of more
investigation.