Sulphates in Shampoo
According to the National Center for Biotechnology Information , a sulphate is sulfur oxoanion obtained by deprotonation of both OH groups of sulfuric acid. This can be interpreted as a salt or ester of sulfuric acid.
According to the National Center for Biotechnology Information, a sulfate is a sulfur oxoanion formed by deprotonation of the two OH groups of sulfuric acid. This can be interpreted as a salt or ester of sulfuric acid.
The European Environment Agency further defines sulphate as “a salt or ester of sulphuric acid, widely distributed in nature and often found in the atmosphere“. Sulphates and sulfates are the same.
The EU Environment Agency defines sulfate as "a salt or ester of sulfuric acid, widespread in nature and frequently occurring in the atmosphere." Sulfates and sulfates are the same thing.
The central element in a sulphate is obviously sulphur. Sulphur is a very versatile and reactive non-metal which is regarded as a basic element of life ie, an essential ingredient necessary for the growth and development of all living organisms on earth. No sulphur = no life.
The central element in a sulfate is, of course, sulfur. Sulfur is a very versatile and reactive non-metal that is considered a basic element of life , that is, an essential component necessary for the growth and development of all living organisms on Earth. No sulfur = no life.
Hair is mainly made of keratin with a high composition of an important sulphur containing amino acid called cysteine. The formation of disulphide bonds between cysteine residues gives hair (keratin) its strength, stability and elasticity. Sulphur is essential for healthy hair.
Hair is made primarily of keratin with high levels of an important sulfur-containing amino acid called cysteine. The formation of disulfide bonds between cysteine residues gives hair (keratin) its strength, stability and elasticity. Sulfur is essential for healthy hair.
Sulphur in Shampoo
Shampoos are used to remove dirt, dust, residues of haircare products, excess sebum or dandruff etc. from the hair. Sebum and other oily products are water insoluble and cannot be removed by water alone. Therefore surfactants or a combination of surfactants are used in shampoos to remove water-soluble and water-insoluble residues/dirt from the hair.
Shampoos are used to remove dirt, dust, residues of hair care products, excess sebum or dandruff, etc. from the hair. Sebum and other oily products are water insoluble and cannot be removed by water alone. Therefore, surfactants or a combination of surfactants are used in shampoos to remove water-soluble and water-insoluble residues/dirt from the hair.
Surfactants do this by weakening the physiochemical forces that bind dirt and impurities to the hair or by dissolving the impurities themselves, thereby preventing them from binding to the hair or scalp.
Surfactants do this by weakening the physiochemical forces that bind dirt and impurities to the hair, or by dissolving the impurities themselves, preventing them from bonding to the hair or scalp.
Surfactants in Shampoo
Surfactants are basically a chain of fatty hydrocarbons with a polar head. The polar head is hydrophobic (fat-loving) and the chain is non-polar or hydrophilic (water-loving). This unique dual extremity makes surfactants an ideal ingredient for cleansing water soluble & fat soluble dirt from the hair.
Surfactants are basically a chain of fatty hydrocarbons with a polar head. The polar head is hydrophobic (fat-loving) and the chain is non-polar or hydrophilic (water-loving). This unique dual extremity makes surfactants an ideal ingredient for cleaning water- and fat-soluble dirt from hair.
Depending on the extremity of charges of the polar head, surfactants can be classified into the following groups: Anionic, cationic, amphoteric and nonionic. Sulphate based anionic surfactants are the most common of the anionic surfactants.
Depending on the extreme charge of the polar head, surfactants can be divided into the following groups: anionic, cationic, amphoteric and non-ionic. Sulfate-based anionic surfactants are the most common of the anionic surfactants.
Sulphates in Shampoo
It is important to understand how surfactants in general work to better analyse sulphate surfactants used in shampoos. As previously explained, surfactants have a water and fat loving part. In the presence of water (ie, when we shampoo in the bathroom), the surfactants attain a structural formation of a micelle. Simply put, a micelle is a cluster of surfactant molecules, with the polar part attaching to water and the non-polar part attaching to oil/fat.
It is important to understand how surfactants work in general to better analyze the sulfate surfactants used in shampoos. As previously explained, surfactants have a water-loving part and a fat-loving part. In the presence of water (e.g. when shampooing in the bathroom), the surfactants form a micelle structure. Simply put, a micelle is a collection of surfactant molecules, with the polar part attaching to water and the non-polar part attaching to oil/fat.
This cluster has the additional effect of reducing the surface tension of water which then enables dirt to be washed out. The foam or suds formed by the lather also reduces the surface tension of water somewhat also allowing for easier removal of dirt.
This cluster has the additional effect of lowering the surface tension of the water, making it easier to wash out dirt. The foam created by the foam also lowers the surface tension of the water, making it easier to remove dirt.
Irritation potential of Sulphates Irritation potential of sulphates
There is a view in the curl community that sulphates, especially sodium lauryl sulphate (SLS), is bad for hair with the recommendation to use “mild” or “non-sulphate” shampoos instead. There is some truth in this, especially with SLS which can aggravate skin conditions in people with sensitive skin because of its ability to clean too well and denature skin proteins.
There is a belief in the curly community that sulfates, particularly sodium lauryl sulfate (SLS), are bad for hair, and it is recommended to use "mild" or "sulfate-free" shampoos instead. There is some truth to this, especially with SLS, which can worsen skin problems in those with sensitive skin because it cleans too well and denatures skin proteins.
However, there is no scientific definition of mildness. What we know is that mildness is defined as an absence of skin irritation, swelling, pain, skin sensitisation or other negatives. The experience with shampoo is therefore based on the specific individual in question. Without a skin patch, there is no definitive way to categorise mildness of different sulphate-based shampoos. Newer non-sulphate shampoos have no data backing their effectiveness and or safety. There are proven ways to make good cleansing shampoos without the dryness.
However, there is no scientific definition of mildness. What we do know is that mildness is defined as the absence of skin irritation, swelling, pain, skin sensitization, or other negative characteristics. So the experience with the shampoo depends on the individual. Without a skin patch, there is no definitive way to categorize the mildness of different sulfate-containing shampoos. For newer, non-sulfate shampoos, there is no data to support their effectiveness or safety. There are proven ways to make good cleansing shampoos without drying out the skin.
See below: See below:
- Lips et al built a model to determine structure-activity between surfactant concentration and its ability to denature proteins and cause skin irritation. The model demonstrated the ability of a surfactant to denature proteins increased with its charge density and skin irritation potential aka. zein dissolution scores. In addition, the irritation ability of a surfactant also increases with the concentration of the surfactant in the shampoo. Lips et al. built a model to determine the structure-activity relationship between surfactant concentration and its ability to denature proteins and cause skin irritation. The model demonstrated that the ability of a surfactant to denature proteins increases with its charge density and skin irritation potential aka. zein dissolution scores. In addition, the ability of a surfactant to cause skin irritation also increases with the concentration of the surfactant in the shampoo.
- Research show that blending different types of surfactants can create “mixed micelles” with the individual surfactants exhibiting less affinity for skin/hair protein, which also reduces the zein dissolution scores. However, low zein values does not always correspond to low skin irritation potential. Research show that blending different types of surfactants can create “mixed micelles” with the individual surfactants exhibiting less affinity for skin/hair protein, which also reduces the zein dissolution scores. However, low zein values does not always correspond to low skin irritation potential.
- Incorporating oils and butters in shampoo formulations as demonstrated in this study and this study , can reduce irritation potential from sulphate shampoos. Incorporating oils and butters in shampoo formulations as demonstrated in this study and this study , can reduce irritation potential from sulphate shampoos .
- Adding proteins in shampoo formulations reduce the tendency of sulphates to react with proteins in the skin/hair
- Anionic shampoos are suitable for the deposition of conditioning cationic polymers in shampoo formulations. Cationic polymers condition the hair by improving manageability, lustre, and health of hair.
Key takeaways when formulating with Sulphates. Important takeaways when formulating with sulphates.
- Avoid sulphate shampoos with just one main surfactant especially sodium lauryl sulphate. This surfactant is very effective but can also strip the hair and skin of moisture and oils.
- Combine milder forms of surfactants eg, (sodium coco sulphate) with other non-ionic surfactants. In these formulations, make the sulphate the secondary surfactant.
- Add oil, protein and conditioning cationic polymers to shampoo to further reduce irritation potential in the formulation.
- Apply shampoo on wet hair after dispersing it first in the hand. Rinse thoroughly with water afterwards.
If at this point you are wondering why go through all this when we can simply use non-sulphate shampoos? Well it's not that easy. Remember, the polar head of the anionic surfactants (aka sulphates) have great affinity for fat/oil. When you imagine sebum (a waxy, highly viscous substance) sitting on layers of products attached to all the dirt, dust, dead skin cells and dandruff, blocking your pores and forming the right conditions for inflammation, scalp issues and even hairloss, you would appreciate how important it is to use the right shampoo. There is no substitute for a clean scalp.
If you're wondering why all this when we can just use sulfate-free shampoos? Well, it's not quite that simple. Remember that the polar head of anionic surfactants (also called sulfates) has a great affinity for fat/oil. If you imagine sebum (a waxy, highly viscous substance) sitting on top of layers of products clinging to dirt, dust, dead skin cells and dandruff, clogging pores and creating the right conditions for inflammation, scalp problems and even hair loss, you'll understand how important it is to use the right shampoo. There is no substitute for a clean scalp.
Recommendations about avoiding shampoos formulated with some sulphate based surfactant is not based on real empirical science. Most of the studies on the internet were conducted with concentrated solutions of surfactant, left on the skin/hair for hours and does not realistically reflect how shampoos are used in real life. As with any chemical, moderation is key. You could die from drinking too much water. Some people are allergic to water! Our skin and hair come in different types and shapes. There is no one model that fits all.
Recommendations to avoid shampoos containing sulfate surfactants are not based on real empirical science. Most studies online were conducted using concentrated solutions of surfactants left on the skin/hair for hours and do not realistically reflect how shampoos are used in real life. As with any chemical, moderation is key. You could die if you drink too much water. Some people are allergic to water! Our skin and hair come in different types and shapes. There is no one model that fits all.
The International Journal of Toxicology on its evaluation of the safety of SLS concludes that “SLS is safe in formulations designed for discontinuous, brief use followed by thorough rinsing from the surface of the skin“. This evaluation was based on formulations with up to 10% SLS!
The International Journal of Toxicology, in its assessment of the safety of SLS, concludes that "SLS is safe in formulations designed for intermittent, brief application followed by thorough rinsing from the skin surface." This assessment is based on formulations with up to 10% SLS!
Conclusion Conclusion
It is important to remember that a shampoo should not be judged based on just one surfactant. The net result of combining different surfactants and other ingredients in a product is what matters.
It is important to remember that a shampoo should not be judged on the basis of a single surfactant alone. What matters is the net result of the combination of different surfactants and other ingredients in a product.
The formulation of shampoos has evolved over the years as more research and knowledge has become available. The key here is to maintain clean, healthy scalp and hair without the added negative of irritation and dryness.
Shampoo formulas have evolved over the years as more research and knowledge has become available. The most important thing is to keep the scalp and hair clean and healthy without causing irritation and dryness.
Milder sulphates in shampoos are safe to use when properly formulated. Milder sulphates in shampoos are safe to use when properly formulated .
Research
1.https://www.sciencedirect.com/topics/nursing-and-health-professions/sulfur 2.https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4387693/ 3.https://www.researchgate.net/publication/309372217_Keratin4. https://www.sciencedirect.com/topics/chemistry/cysteine
5. https://www.sciencedirect.com/topics/biochemistry-genetics-and-molecular-biology/disulfide-bond
6. https://www.sciencedirect.com/topics/chemistry/shampoo
7. https://www.sciencedirect.com/topics/nursing-and-health-professions/sulfur
8. https://journals.sagepub.com/doi/pdf/10.1177/1091581810364665
9. https://www.ema.europa.eu/en/documents/report/background-review- sodium-laurilsulfate-used-excipient-context-revision-guideline-excipients- label_en.pdf
10. https://www.researchgate.net/publication/331789745_Sodium_Lauryl_Sulfate_vs_Sodium_Coco_Sulfate_Study_of_the_Safety_of_Use_Anionic_Surfactants_ with_Respect_to_Their_Interaction_with_the_Skin
11. https://www.naturallycurly.com/curlreading/curl-products/curlchemist-surfactants-sulfates-and-you
12. https://onlinelibrary.wiley.com/journal/14682494
13. https://www.researchgate.net/publication/343254889_The_involvement_of_ protein_denaturing_activity_in_the_effect_of_surfactants_on_skin_barrier_function
Disclaimer – legal information
1. limitation of liability. The contents of this website have been prepared with the greatest possible care and to the best of our knowledge. Nevertheless, the provider of this website does not assume any liability for the topicality, completeness and correctness of the pages and content provided.The content of this blog cannot be regarded as medical advice.
2. External links. The website contains so-called "external links" (links) to other websites over whose content the provider of the website has no influence. For this reason, the provider cannot assume any liability for these contents. The respective provider of the linked website is responsible for the content and accuracy of the information provided. At the time of linking no legal violations were apparent. If any such infringement becomes known, the link will be removed immediately.
3. Copyright/performance protection law. The contents, works and information published on this website are subject to German copyright and ancillary copyright law. Any kind of reproduction, editing, distribution, storage and any kind of exploitation outside the limits of copyright law requires the prior written consent of the respective copyright holder. Unauthorised copying/saving of the information provided on these web pages is not permitted and is punishable by law.