About 85% of toothpaste contains SLS as a surfactant ingredient for the simple reason it is cheap and very effective. Despite its popularity with toothpaste manufacturers, SLS has gained a negative reputation as a harmful chemical that should not be allowed anywhere near your teeth, hair, or skin. In this article, I take a closer look at the controversy surrounding SLS and compare it to the evidence-based research.

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Sodium lauryl sulfate, or SLS for short, is a chemical compound prepared by sulfation of lauryl alcohol and neutralized with sodium carbonate, it is also commonly known as Sodium dodecyl sulfate (SDS). Sodium lauryl sulfate belongs to a group of chemical compounds called surfactants that are commonly used as detergents, wetting ingredients, thickeners, and emulsifiers. SLS is extensively used in household cleaning products as well as a whole range of personal care products such as soap, shampoo, moisturizers, bath products, shaving products, toothpaste, and mouthwash.

Popular viral claims regarding SLS include –

• Skin and eye irritant – This is actually true! SLS is a recognized irritant that can cause discomfort to people with sensitive or hypersensitive skin.  It must be stressed that when used appropriately and at the correct concentrations, most people can use products that contain Sodium lauryl sulfate without any problems, this is especially true of products like shampoo or soap, where it is mostly all washed away by the rinsing effects of water. However, the practice of exposing the delicate and sensitive lining of the mouth to a toothpaste containing harsh, synthetic chemicals like SLS is questionable.
• Causes cancer – This is false! Sodium lauryl sulfate (SLS) is not classified as a carcinogen by any health organization. There is no evidence to suggest that SLS is in any way linked to cancer.
• Causes hair loss – This is false! Research has shown that high concentrations of SLS applied to the skin of laboratory rats left heavy deposits on the hair causing potential damage to the hair follicles but there is no evidence to suggest resulting hair loss.
• SLS can be absorbed into the bloodstream – This is true! Although most of the chemical is left on the outside of the skin, it is possible for some SLS to be absorbed into the bloodstream.
• Organ toxic – This is false! While it is true that SLS can be absorbed into the bloodstream there is no data to suggest that it accumulates in vital organs. SLS deposits in the blood are quickly cleaned up by the liver and excreted from the body.
• Neurotoxic – This is false! There is no evidence to suggest that SLS absorbed into the bloodstream can affect the nervous system. TOXNET® does not recognize SLS as a suspected neurotoxin.
• Reproductive toxic – This is false! There is no substantiation to claims that SLS can affect normal reproduction.
• Harmful to the environment – This is true! Although this is technically true and SLS in its raw state is moderately toxic to aquatic life it can be argued that the low concentrations found in household and personal care products could be considered non-toxic. The toxicity of SLS to aquatic organisms also depends on specific water parameters such as hardness and temperature.

Despite all the sensational claims and clickbait headlines, major health organizations generally accept that SLS does not pose any significant health risk provided it is used correctly at the recommended concentration levels. The American Cancer society rubbished claims that SLS causes cancer in 1998 and no research since then has linked SLS in any form or concentration to cancer. None of the international organizations such as the World Health Organization, European Union or US Environment Protection Agency have classified Sodium lauryl sulfate as a carcinogen. The CIR ( Cosmetic Ingredient Review) Expert Panel re-reviewed Sodium lauryl sulfate and its usage amid the viral allegations that it is toxic and carcinogenic to humans.  Even after examining all the data they still found no reason that SLS would pose any health risk when used in cosmetic and personal care products. The FDA Sec.172.822 (Reviewed 1 April 2017) still permits the use of Sodium lauryl sulfate (SLS) as a thickening and emulsifying additive to foods provided it is used within the stipulated guidelines. Suggestions that Sodium lauryl sulfate (SLS) is organ toxic, neurotoxic or a reproductive toxic when ingested or absorbed through the skin are completely unfounded.

Sodium lauryl sulfate (SLS) serves a number of purposes when used to formulate toothpaste –

• It helps to provide the rich foamy toothbrushing experience that most people have become used to when cleaning their teeth.
• It provides the mechanism for bringing active ingredients like fluoride into contact with the teeth for the longest possible time.
• It helps to lift and remove the sticky plaque biofilm from the teeth surface and leave them feeling squeaky clean.

SLS is not exactly an essential toothpaste ingredient that you can’t do without, it is definitely possible to give your teeth a perfect clean without it. However, there are some possible disadvantages if you don’t choose your SLS free toothpaste carefully. Here is a list of advantages as well as disadvantages of using SLS free toothpaste.

Advantages of using an SLS free toothpaste –

• SLS is a harsh detergent that will come in contact with your delicate mouth lining twice a day 365 days a year. By switching to an SLS free toothpaste, you will reduce your chemical exposure.
• If you are prone to canker sores, replacing your regular toothpaste with an SLS free alternative could decrease discomfort and quicken recovery time.
• If you have gum disease, switching to a milder or more natural toothpaste can help to avoid exasperating your already inflamed gum tissue.
• If you suffer from sensitive teeth, swapping SLS toothpaste for non-SLS toothpaste can help reduce sensitivity pain. Imagine if you had a paper cut on your finger and you rubbed detergent into it, it would sting! Brushing SLS onto sensitive teeth, infected gums, or canker sores can have the exact same effect.
• Sodium lauryl sulfate (SLS) has been shown to reduce the anti-cavity effectiveness of fluoride on teeth enamel. By using an SLS free toothpaste you can gain the maximum benefit from its fluoride active ingredient.
• It is common for manufacturers of SLS free toothpaste to be more socially and environmentally aware. Companies like Green People and Dr. Bronner’s are committed to sourcing natural, sustainable and fair trade ingredients.

Disadvantages of using an SLS free toothpaste –

• SLS is very effective at what it does. It has excellent foaming and cleaning properties that leave the teeth feeling very fresh and clean. Some SLS free toothpastes do not have a comparable surfactant system and as a result, do not leave the teeth feeling quite as clean. This doesn’t mean the teeth aren’t clean, they just feel different and this can be disconcerting for some users.
• SLS is an excellent foaming agent that makes it very easy to brush toothpaste into all areas of the mouth. By contrast, some SLS free toothpastes are very low foaming, weak, and watery. This can make it more difficult to clean teeth since it doesn’t have the same heavy consistency.
• One reason for Sodium lauryl sulfate (SLS) being such a popular ingredient with manufacturers is that it is cheap to produce. Alternative SLS free toothpaste formulations can be more expensive to produce and often retail at a higher cost to the consumer.
• Often, the more “natural toothpaste” that doesn’t contain SLS also lacks the preserving qualities of more synthetic toothpaste and as a result, has a shorter shelf life.
• Some alternative surfactants that are used instead of SLS have a very unpleasant taste, as a result manufacturers often resort to using very strong flavorings just to make to toothpaste seem more pleasant. Some of these flavorings can be too harsh for people with sensitive mouths.

Picking an SLS free toothpaste can be difficult and confusing. For starters, ingredient labels are usually not user-friendly and sometimes manufacturers use synonyms that you may not be familiar with. Sodium lauryl sulfate can also be called –

• Sodium dodecyl sulfate
• Sulfuric acid monododecyl ester
• Dodecyl hydrogen sulfate sodium salt

There is also similar sulfate-based chemicals like Sodium Laureth Sulfate(SLES) that have slightly different properties but still have the same foaming and cleaning properties. SLES is produced by the ethoxylation of dodecyl alcohol and is considered to be a slightly less irritating surfactant than SLS, although it has faced much of the same viral criticism as SLS. There is some extra concern regarding Sodium Laureth Sulfate(SLES) in that there is potential for 1,4-dioxane contamination during the ethoxylation process. Although traces of 1,4-dioxane would be lower that which would be considered a threat to health it is understandably a concern for consumers.

Most kinds of toothpaste available today are complex synthetic formulations that have been carefully blended to give a pleasant texture and taste while at the same time dispersing throughout the oral cavity to help make the mouth feel as fresh as possible. Concerns over the health implications of ingredients like SLS is inspiring people to search for a more natural toothpaste that can rival regular synthetic brands in term of effectiveness and experience. If you want to replace your regular toothpaste with an SLS free alternative, these are some of the important characteristics to look for –

• The toothpaste should have adequate foaming properties to give a cleaning experience that is as good as or better than an SLS toothpaste.
• The taste of the toothpaste should be acceptable to both adults and children.
• The toothpaste should not use very strong artificial flavorings just to mask a foul-tasting surfactant.
• The shelf life should be adequately long so that the product does not deteriorate before it has been used.

• Coco-glucoside – An excellent toothpaste surfactant that ticks all the boxes for people who want a “green” alternative to SLS. It is non- irritating and doesn’t dry the skin in the way that sulfate surfactants do, making it well suited for products that come into contact with mucal membrane areas like the inside of the mouth. Coco-glucoside is what is known as an Alkyl Glucoside and it can be regarded as a green ingredient since it is derived from natural, renewable raw materials  It is produced by reacting the alcohol from coconut or palm oil with glucose from corn, potatoes or wheat starch.
• Sodium Cocyl Glutamate – Although this is also derived from coconut oil it can’t be described as a natural or organic ingredient. Sodium Cocyl Glutamate is still a synthetic surfactant that is relatively similar to Sodium lauryl sulfate (SLS). However, it is milder and less irritating to the skin than SLS.
• Sodium Methyl Cocoyl Taurate – This is another popular SLS alternative used by brands like Eco-dent, With My and Kiss my Face. Sodium Methyl Cocoyl Taurate is a mild and stable surfactant that has excellent foaming capabilities but without the irritating characteristics.
• Decyl Glucoside –  A mild and gentle ingredient that is similar in nature to Coco-glucoside. This is a popular ingredient in personal care products because of its non-irritating and non-allergenic qualities.  For consumers who want more natural ingredients in their toothpaste, Decyl Glucoside fits the bill perfectly. It is a biodegradable surfactant produced from plant-based oils, sugars and starches. Used in toothpaste EMIKO®Care.
• Quillaja triterpenic saponins – Another natural foaming agent that can be used in toothpaste as a replacement to SLS. This ingredient is extracted from tree bark that can be produced from eco-friendly forests. The foaming properties are relatively poor compared to SLS so this ingredient is sometimes used in conjunction with other surfactants like Sodium Lauroyl Sarcosinate.