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Last updated on April 8th, 2019
Cocamidopropyl Hydroxysultaine is one of many newly emerging surfactants. A surfactant (aka cleansing agent) is an ingredient that creates lather and makes your shampoo or body wash foam. It is now commonly used in shampoos, bath washes, and detergents.
Today you will learn about the latest research into its safety so you can make an informed decision whether you want this ingredient in your personal care products.
Cocamidopropyl Hydroxysultaine Research
Cocamidopropyl Hydroxysultaine is rated 1 with limited data in the Skin Deep database powered by the Environmental Working Group. While this is one of the most helpful tools to assess product or ingredient safety, it has some shortcomings. For example, ingredients that have no data or limited data tend to have a rating of 1 out of 10 (with 1 being the safest). And sometimes the Skin Deep database does not reflect the latest research or product ingredients.
In the case of Cocamidopropyl Hydroxysultaine, in 2018 the Cosmetic Ingredient Review (CIR) Expert Panel issued a safety report, the findings of which have not yet been reflected in the Skin Deep database.
Before we talk about the CIR report, let me tell you a few words about the Cosmetic Ingredient Review Expert Panel. It is an industry-sponsored agency. So, while the reports are helpful and a good source of scientific studies, when you read them, keep in mind that the Panel is not independent of the industry.
When I research a product or an ingredient, I look at a variety of sources, including rating databases, CIR reports, and the latest independent studies published in scientific journals. I find it very helpful to go directly to the source. I am able to do that because this is what I do for a living, so you do not have to. I know nobody has time for this unless you become a full-time researcher. Please look around my website. You might find helpful services which you can take advantage of.
Cosmetic Ingredient Review Expert Panel report
Let me tell you the important points from the CIR report of 2018.
- Cocamidopropyl Hydroxysultaine was found to be genotoxic in concentrations up to 50%.
- There are no published studies as to whether it might be carcinogenic.
- It was predicted to be a severe ocular (i.e. eye) irritant.
- Cocamidopropyl Hydroxysultaine was found to be not a skin irritant in animal studies in concentrations up to 41.5%.
- In a patch test using a concentration of 4% on 51 healthy volunteers, no irritation or sensitization was observed.
- Slight to moderate irritation was observed after repeated patches in a 2.5% concentration in 45% of 44 healthy people.
- Cocamidopropyl Hydroxysultaine (1%) yielded positive patch tests in a patient that experienced eczema following use of 2 shampoos that contained this ingredient.
The Panel concluded that the sensitization potential of this ingredient is very low. If sensitization occurs, it is most likely due to the contaminant, 3,3-dimethylaminopropylamine (DMAPA).
How Cocamidopropyl Hydroxysultaine is produced
Sometimes, knowing how an ingredient is made is as important as knowing what it is made of. For example, when manufacturers boast that a certain chemical is made from (or “derived from”) coconut oil, it sounds pretty healthy, right? Unfortunately, it’s not that simple.
Cocamidopropyl Hydroxysultaine is produced using a multi-step process where chemicals are added to produce intermediary chemicals. As a result, contaminants may be present in Cocamidopropyl Hydroxysultaine. Specifically, 3,3-dimethylaminopropylamine (DMAPA) is a cause for concern even in very small amounts, because it is a sensitizer.
According to the CIR report, one supplier of Cocamidopropyl Hydroxysultaine reported that it contains typically less than 2 ppm (parts per million) of DMAPA. Another supplier has reported that unreacted free DMAPA is typically less than 10 ppm.
To ensure that sensitization is minimized, the Panel urged manufacturers to minimize the content of DMAPA.
Because the CIR report is very recent, it is not surprising that I have not found any scientific studies in addition to the ones described in the CIR reports.
Cocamidopropyl Hydroxysultaine’s Relative
The reason that there are not many studies into this ingredient might be that it is new. After reading numerous shampoo ingredients, I noticed that it is often used instead of Cocamidopropyl Betaine. Notice that they both share the same first word in their names. In fact, the CIR report states Cocamidopropyl Hydroxysultaine is structurally related to Cocamidopropyl Betaine.
And they share the same concerning contaminant, DMAPA. Cocamidopropyl Betaine has been studied a lot better than Cocamidopropyl Hydroxysultaine. The CIR Panel issued two reports on Cocamidopropyl Betaine, in 1991 and in 2012. The latest report states that the Panel recognizes that Cocamidopropyl Betaine has the potential to induce skin sensitization, most likely due to the contaminants DMAPA and amidopryl dimethylamine (amidoamine). Hence, the Panel advised manufacturers to continue minimizing the concentration of the sensitizing impurities.
In addition, dermatologists in the Netherlands recommend that hairdressers, when they use products containing Cocamidopropyl Betaine, should patch test for Cocamidopropyl Betaine allergy.
The American Society of Contact Dermatitis lists Cocamidopropyl Betaine as one of the core allergens, even in concentrations as low as 1%. Due to high rates of cases involving allergic reactions, it was named the 2004 Allergen of the Year by the American Contact Dermatitis Society.
The EWG issued a rating of 4 to Cocamidopropyl Betaine, in contrast to its rating of 1 to Cocamidopropyl Hydroxysultaine (source).
Conclusions about Cocamidopropyl Hydroxysultaine
In conclusion, I believe that the concerns of sensitization toward Cocamidopropyl Betaine are related to Cocamidopropyl Hydroxysultaine. We should not think the lack of data makes Cocamidopropyl Hydroxysultaine a safer alternative to Cocamidopropyl Betaine. In my Shampoo Rating List, I give it a rating of 3 out of 10 (with 10 being the worst) versus the rating of 1 in the Skin Deep database.
On the other hand, in the big scope of things, despite its potential for sensitization, it is not one of the worse surfactants in my opinion. Unfortunately, numerous other surfactants in shampoos have some concerns or lack sufficient data (and some have no data at all). I recommend you proceed with caution and discontinue a product if irritation occurs. And I would not use baby shampoos and washes containing this ingredient on babies. Traditional and natural soap bar is the safest washing product for a baby and for us. To read more about shampoo bars and why I can’t use them on me, please visit here.
Your Superpower To Read Ingredients
Imagine looking at the ingredients of any shampoo, conditioner, lotion, or cream and in a matter of seconds being able to decide if it is safe to use!
With this easy unprecendented method, you will be able to spot potentially harmful personal care or skincare products that may cause irritation, an allergic reaction, or increase the risk of endocrine disruption or cancer.