SLS: The Dirty Truth Behind The Suds

Apr 27

For many years, even decades, SLS has been viewed as a toxic ingredient in our soaps and detergents — but is this actually true? We’re going to explore the dirty details of Sodium Lauryl Sulfate and review readily available information to further understand this unanswered question.

I think we should first address the break-down of SLS and explain what it is made up of. The National Institutes of Health defines SLS as: “SLS can be synthetic or naturally derived. This chemical is synthesized by reacting lauryl alcohol from a petroleum or plant source with sulfur trioxide to produce hydrogen lauryl sulfate, which is then neutralized with sodium carbonate to produce SLS”.

Here is list of definitions explaining the terminology within that description so we have a better understanding of its meaning.

Synthetic (Chemical synthesis): Controlled chemical reaction(s) that take place from multiple molecules being combined in order to produce a more complex product.

Naturally Derived: The reaction starts out with a natural component of the earth, but is then chemically altered in a controlled manner.

Lauryl Alcohol (Dodecanol): An organic compound produced industrially from coconut oil or palm kernel oil. It is a commercially made fatty alcohol.

Sulfur Trioxide: An acid that is a highly reactive inorganic compound made up of sulfur + oxygen and it comes in many forms.

Hydrogen Lauryl Sulfate: an acidic surfactant.

Sodium Carbonate: is a water-soluble salt that is used as a neutralizer. Can be natural or formed synthetically by combining table salt and limestone; also known as the Solvay Process.

Having the information above can help us write our own basic definition of how SLS is created:

A controlled reaction takes place by combining an oily substance (that was either synthetically created or came from a natural component) with an acid — creating an acidic surfactant. A salt is then added to neutralize acidity and leaves us with Sodium Lauryl Sulfate.

Okay, so we have a better idea of how SLS is formulated and it seems kind of harmless… Right?

There was one word that doesn’t sit right with most people in our basic definition and that was the word SYNTHETIC. I know we defined synthetic above, but how does this apply in creating SLS? Besides the synthesized chemical reaction in creating SLS, the other synthetic part of SLS is pulling lauryl alcohol from petroleum-based sources. Petroleum is a non-renewable resource since it comes from crude oil, natural gas, and other fossil fuels. It can be difficult though to know what type of petroleum is being used in synthetic SLS, as the location and the refining process that is being done is dependent on the manufacturer and type of processing. The one most commonly used in SLS is lubricating oil. In general, petroleum-based lubricating oils are toxic to the environment and can create acute toxicity to humans in the form of a skin irritant. These lubricating oils are also a known carcinogen when there is long-term exposure to breathing in mist of the fumes, according to the National Cancer Institute. But when these lubricating oils are super refined during processing (think food-grade mineral oil used to hydrate cutting boards and even lotions), they are safe and considered non-toxic to humans by the FDA. With all this said, the big takeaway from the petroleum topic is that, whatever household or body products that you use containing SLS — you can research the business practices of the specific company/brand you have purchased those products from in order to understand their values and processes.

I know what you’re thinking though… “That seems like a lot of work.” If you decide to go the non-tedious route, you have the option to choose products containing SLS with the description of *Naturally Derived. As we explained earlier, naturally derived sodium lauryl sulfate is taking lauryl alcohol from a natural source, such as coconut oil or palm kernel oil. Though these are great alternatives, cultivating palm oil does have negative environmental impacts such as deforestation, water pollution, destruction to habitats causing wildlife displacement, and harm to indigenous communities. The climate change contribution is also a worry due to the the enormous amounts of carbon dioxide that is released into the atmosphere. Fortunately, there are changes happening globally in production of palm kernel oil, as many companies are gaining certification in responsible and sustainable practices by following strict criteria set up by the Roundtable on Sustainable Palm Oil organization. If you’re wanting to avoid palm kernel oil completely, you can look for another version of sodium lauryl sulfate in your soap called Coco Sodium Sulfate (CSS) that strictly uses lauryl alcohol from coconut oil.

Based on all of the information that we now know, Sodium Lauryl Sulfate might not be as bad as well all thought and can be a safe ingredient in our soaps if made ethically. It can also be a skin irritant, due to its oil stripping properties.

There is another form of SLS called Sodium Laureth Sulfate (SLES) and this is the one we should be worried about. Sodium Laureth Sulfate’s creation starts out like SLS, but there is one small difference that makes it toxic — the Ethoxylation process. What the heck is Ethoxylation? It is when a flammable gas called Ethylene Oxide is added during the first step of the SLES formulation to make a chemical less harsh. Weirdly, this sounds counterintuitive, but science is crazy y’all! It is commonly used in products like antifreeze, adhesives, and sterilizers. As far as personal care products, it is used in shampoos, hand soap, and toothpaste. It can also be shown on ingredients labels as Polyethylene Oxide and Polyethylene Glycol (PEG). Ethylene Oxide is recognized by the EPA as a carcinogen through inhalation and has shown higher levels of breast and lymphoid cancer in females based on occupational studies. To put into perspective the amount of inhalation you would have to take in of ethylene oxide to potentially end up with cancer would be continuously breathing in one cube of concentrated air that measured one meter on each side/ the weight of one grain of sand throughout your life. This would give you a potential 1 in 10,000 chance of developing cancer.

The United States has very little regulations on chemicals within our household items which is pretty scary, therefore, we don’t know what the percentage of chemicals and compounds such as ethylene oxide are being added to our products like soap. I realized that we essentially talked about toxic inhalation, but we should touch on the matter of Toxic Load. A basic definition of this would be the build up of toxins in our bodies that we ingest through the air, liquids/food, and skin. We are exposed to toxins on the daily and as life as goes on, those toxins accumulate within our organs, bones, and tissue that never really leave. Once these vital parts of us are overwhelmed with harmful substances and our bodies can no longer filter out the bad stuff, we begin to succumb to illnesses that we just can’t fight off. Therefore, if we are constantly using toxic skin, hair, and household products repeatedly on our skin, it can become just as serious as toxic concentrated inhalation.

Here is a list of other common carcinogen ingredients within household and personal care products:

PEG-5 Cocoate (1,4-Dioxane)
Ethylene glycol
Polysorbate-20
Tetrasodium Glutamate Dictate
Diethanolamine (when mixed with a preservative)
Triethanolamine (when mixed with a preservative)

One great way to avoid as many of these chemicals as possible is to make your own soaps! It can be a little bit of a rollercoaster to get the process down to a T, but knowing exactly what your products are made up of without any other “fillers” is certainly a mental comfort. There are endless blogs and recipes online that you can read up on to learn how to create your own at-home products. This is why we here at Colorado House Cleaning make our own cleaning products — to make sure your home and our hands are free of toxic chemicals during house cleaning services!

Sources:

National Library of Medicine

Human and Environmental Toxicity of Sodium Lauryl Sulfate (SLS): Evidence for Safe Use in Household Cleaning Products

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4651417/#:~:text=SLS%20can%20be%20synthetic%20or,sodium%20carbonate%20to%20produce%20SLS

National Library of Medicine

Ecological and Health Effects of Lubricant Oils Emitted into the Environment

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6720566/

National Cancer Institute

Mineral Oils: Untreated and Mildly Treated

https://www.cancer.gov/about-cancer/causes-prevention/risk/substances/mineral-oils

Roundtable on Sustainable Palm Oil

Why Sustainable Palm Oil?