Cosmetic companies and the FDA don’t seem to have a problem with Sodium Lauryl Sulfate (SLS) and Sodium Laureate Sulfate (SLES), so why should I? You may have heard about these two chemicals, but didn’t know why people do what they can to avoid them. Here’s the deal so you can make a decision for yourself and your family:
What is Sodium Lauryl/Laureth Sulfate, where is it found, and where does it come from??
Both SLS and SLES are foaming agents and surfactants used for cleaning. They are commonly found in:
- Foaming cleaning agents
- Liquid hand soaps and shower gels
- Laundry detergent
- Dish soap
Both SLS and SLES are synthesized from lauryl alcohol, which can be derived either from plants or petroleum. Regardless of the source of the lauryl alcohol, in the end they are always highly processed and mixed with other chemicals to create SLS and SLES.
What is the difference between SLS and SLES?
SLES differs from SLS by one oxygen molecule and is created by adding ethylene oxide to SLS. Through this process, called ethoxylation, a harmful bi-product called 1,4-dioxane is created. Some manufacturers will attempt to reduce the 1,4-dioxane in SLES, but it is not completely removed. SLES is less irritating to the skin, but potentially more dangerous.
SLS or SLES? Which is safer to use?
According to several sources, neither one are great. Both are known irritants. While SLS is known to be an irritant, SLES is known to often contain a by-product called 1,4-dioxane. This by-product is a likely carcinogen and the FDA has recommended all cosmetics manufacturers “reduce” the dioxane contained in their products, though it is not required by law. According to the FDA, the cosmetic industry was aware of the presence of this harmful chemical in 1982. However, SLES is also still a major source of 1,4 dioxane. Consumers can identify potential products with 1,4 dioxane by looking for these ingredients: PEG, polyethylene, polyethylene glycol, polyoxythylene, oxynol, ceteareth, oleth, -xynol, -eth
What are the specific dangers of using SLS/SLES?
Additionally, 1,4-dioxane (the by product created when making SLES which can be present in SLES in varying concentrations) is:
- considered an irritant to eyes, nose and throat (short term)
- to cause nausea, headache, drowsiness (short term)
- likely carcinogenic to humans
- linked to liver and kidney damage (long-term)
Is SLS/SLES safe to use long term?
Though the Cosmetic industry claims that SLS and SLES are safe to use over a short time, there is no definition of what a “short time” is. Most of us shampoo our hair at least three times a week for most of our lives, wash our hands multiple times a day, wash dishes regularly, etc… Therefore, we probably use products with SLS/SLES up to 5-10 times a day for most of our lives… Clearly, safety in the long-term needs to be studied.
However, the results of such tests offer varied results and is difficult to sort through. This leaves consumers confused about what to believe and who to trust:
- Many of the studies and tests are sponsored by the manufacturers of products that use SLS and SLES. They don’t want to find dangers so they test at very low concentrations.
- Many of the studies don’t take into account the actual frequency of using products with SLS/SLES, limiting frequency to “2-3 times a week”
- Many studies are poorly designed, leading to weak claims. So unless you’re familiar with research and analysis, it’s hard to know what’s bogus and what’s not.
- Those attempting to discredit the chemical companies and prove that SLS / SLES are dangerous are usually doing studies with high concentrations. These must be done in vitro (using specimens in petri dishes), because human or animal testing is generally frowned upon.
- Those claiming that SLS and SLES are safe argue that the “in vitro” studies are insufficient proof as they were not done on humans.
Overall, the long-term effects of SLS/SLES are generally unknown. Scientists have also not studied the long-term effects of washing SLS, SLES, and 1,4-dioxane down the drain. They do know that 1,4-dioxane has been found in the groundwater across North America. If both the FDA and Health Canada have recognized it as a carcinogen, then what is it doing to the animals, nature, oceans, and lakes?
Is SLS/SLES stored in our organs and tissues?
As you probably know, our skin (including our scalp), is like a giant sponge. Chemicals applied to the skin are absorbed into the blood stream and then distributed throughout our organs and tissues. Many of the chemicals we encounter are stored and accumulate in our organs over time. As far as I could find, there are no scientific studies which clearly support or contradict that SLS or SLES stores in vital organs. It becomes your decision to take a chance.
What can you do to avoid SLS/SLES?
- Use natural soap bars instead of foaming, liquid hand soaps or shower gels
- Use natural household cleaning products
- Look for shampoos without SLS/SLES
- Other names for SLS to avoid:
- Sodium lauryl sulfate; Sulfuric acid monododecyl ester sodium salt; Sodium dodecyl sulfate; Dodecyl sulfate, sodium salt; Sodium lauryl sulfate ether; Sodium n-dodecyl sulfate; Sodium Lauryl Sulfate
- Other names for SLES to avoid:
- Sodium dodecylpoly(oxyethylene)sulfate; Sodium lauryl sulfate ethoxylate; Sodium polyoxyethylene lauryl ether sulfate; Sodium laureth-8 sulfate; Laureth-8 carboxylic acid, sodium salt; PEG-# lauryl ether sulfate, sodium salt where # is 5,7,8 or 12; Polyethylene glycol (#) lauryl ether sulfate, sodium salt where # is 5,7,12,400 or 600; Sodium laureth-# sulfate where # is 5,7 or 12; Sodium lauryl ether sulfate