Do you know what is the most common ingredient in your skincare? Surfactants! From your cleansers to moisturisers and your makeup products, surfactants are present in most of your cosmetics and personal care products.
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If you're wondering why and whether you should really buy products with surfactants, stay with us till the end of the article. Let's begin.
Surfactants are a primary component of cleaning detergents. As the name suggests, surfactants evoke activity on the surface you are cleaning, to help trap dirt and remove it from the surface.
Your soaps, shampoos and hair conditioners contain surfactants, as they help cleanse your scalp, skin, and hair. These compounds create a pleasantly foamy reaction, when mixed with water. They are usually safe for all skin types.
Beyond soaps and detergents, surfactants are also used in lubricants, inks, anti-fogging liquids, herbicides, adhesives, emulsifiers and fabric softeners.
Let&#;s dig deeper into how surfactants work chemically. Surfactant is the short form of surface active agents. [1] Surfactants act at the interfaces, such as the oil-water interface or air-water interface. It alters the surface tension (molecular forces) between the two fluids. How do they achieve this?
Surfactants are amphiphilic (amphi: both + philia: love) molecules, that is they have two ends:
When surfactants are added to a solution in sufficient concentrations, they reorganize in such a way that the hydrophilic heads are turned towards the water. The hydrophobic tails capture oil or dirt, forming droplets, also known as micelles [2] (as shown in the image below). With this chemical property, surfactants can be excellent detergents, emulsifiers or foaming agents.
Synthetic surfactants are mostly manufactured using starting materials (reactants used in chemical reactions) such as petrochemicals. These further undergo chemical reactions such as sulfonation (addition of sulphur) or ethoxylation (addition of ethylene oxide). Being synthetic in nature, they can be designed or mixed with other chemicals to serve their desired purposes.
However, there is also a range of biosurfactants that have great advantages as an eco-friendly alternative to synthetic surfactants. These are chemicals produced by microorganisms, but have clearly defined hydrophilic and hydrophobic groups.
Biosurfactants occur in nature. Fungi, bacteria, and yeast are known for producing biosurfactants. They can also be derived from plant-based sources such as coconut and palm oil. [3]
Depending on the charge present on the hydrophilic head of the surfactants, they can be divided into four groups: [4]
As the name implies, nonionic surfactants do not yield any net charge in solution. Being mild in nature, these are often the preferred ingredient in cosmetics that do not have foaming or lathering properties.
Nonionic surfactants can be combined effectively with other classes of surfactants. They are commonly used in hand and body moisturisers. Stearyl alcohol, cetearyl alcohol are some of the common nonionic surfactants used in your skincare products.
These are negatively charged surfactants, good at removing oil and dirt from your skin&#;s surface. Anionic surfactants are the most commonly used variety as primary detergents in soaps, shampoos and cosmetics having strong cleansing effects. However, they can also be harsh and irritating to your skin.
Such surfactants are often combined with amphoteric or nonionic secondary detergents to cut down on the harshness. Some examples include, SLS (sodium lauryl sulphate), sodium stearate, alpha olefin sulfonate, etc.
Being positively charged, these surfactants are not effective as detergents and therefore not used in cleansers. The human skin is mostly negatively charged. Thus cationic surfactants tend to attach strongly to it. However, this property makes these surfactants effective carriers of therapeutic products for damaged skin and hair.
Cationic surfactants are also used in fabric conditioners. Quaternary ammonium salts are among the most commonly used cationic surfactants.
These surfactants get their name due to the presence of both positive and negative charges in solution. They can adjust the pH of the environment they are added to. Such surfactants can have a calming effect on your skin.
Amphoteric surfactants might be used as secondary surfactants in skincare products to reduce irritation and increase foaming. Betaines, sulfobetaines, certain amino acids and phospholipids are few commonly used amphoteric surfactants.
Listed below are some commonly used surfactants in skin and hair care products along with their functions:
Surfactant
Function
SLS (Sodium lauryl sulphate) ALS (Ammonium lauryl sulphate) Olefin sulfonates
Cleansers, foaming agents
Sodium stearate
Soap
Stearic acid
Deodorants, antiperspirants
Cetrimonium chloride Stearalkonium chloride
Hair conditioners
Sodium Lauriminodipropionate Disodium Lauroamphodiacetate
Mild cleansing agents for sensitive skin and hair
Cetyl alcohol Stearyl alcohol
Emulsifiers, thickening agents
Cocamidopropylamine oxide
Foaming agent
Polysorbate ester
Solubilising agent
Surfactants are one of the most extensively used ingredients in the cosmetics industry. The varied chemical properties make them extremely beneficial in personal care products.
Let us see some common applications of surfactants in the cosmetic industry.
Because of their amphiphilic nature, surfactants can form micelles that trap oil, dirt or sebum. It loosens them from your skin surface, which can then be easily washed away. They are added in products such as soaps, shampoos and face washes.
Surfactants can be used as emulsifiers, which stabilize the mixture of two immiscible or insoluble liquids such as oil and water, for a prolonged period of time. Emulsifiers are commonly used in creams, lotions, conditioners, etc.
This group of surfactants reduce the surface tension at the air-water interface. They also enhance lather or bubble formation. A good application of these surfactants is in products like shaving creams, which helps soften the stubble for a smooth shave.
Certain surfactants can interact with other ingredients in a formulation, trapping them in a network of the primary surfactant molecules. This results in thickening of the products. These are usually in the manufacture of thick winter body lotions, conditioners for dry hair, mascaras, etc.
These surfactants reduce the intramolecular forces at the liquid interface. They also facilitate spread and penetration of the products containing them into the depths of skin and hair. Wetting or dispersion agents are most commonly used surfactants in cosmetic products.
Some surfactants can render a formulation opaque by absorbing light, and making the surface applied on, look brighter. These are commonly used in makeup formulations.
Cationic surfactants can form a resilient, protective coating on skin or hair surface.They are commonly incorporated into makeup products, hair conditioners, etc.
Due to their bactericidal properties, surfactants can be used as preservatives in cosmetics to prolong their shelf life.
Be meticulous while making a choice of surfactants. Not only do they form a large group of ingredients, but are also used in combination with other surfactants and various other ingredients. The interaction between all the ingredients brings out the final effect of the surfactants on your skin.
Avoid using the harsh ones such as SLS or SLES (Sodium laureth ether sulfate). Harsh surfactants can strip your skin of its natural moisture and hasten your skin&#;s aging process.
Another group of surfactants like PEG (polyethylene glycol), which penetrate deep into the skin, can act as carriers for potential carcinogens (cancer-causing).
Natural surfactants, which are derived from plant sources, are relatively safer to use. They undergo a certain degree of chemical processing in order for them to be suitable for use in cosmetics. Some natural surfactants are potassium cocoate (derived from coconut oil), decyl glucoside (from corn and coconuts), sucrose cocoate (from sugar beets), etc.
Most of SkinKraft&#;s customized skin and hair care products are formulated with natural surfactants derived from coconut or palm oil and corn glucose. They clean your skin and hair gently without stripping off its essential oils.
The company is the world’s best what is a surfactant in skin care supplier. We are your one-stop shop for all needs. Our staff are highly-specialized and will help you find the product you need.
Surfactants present in a product may interact with the skin primarily in two ways:
Surfactants can interact with the stratum corneum (SC), the outermost layer of your skin. The surfactants form monomers or polymers, which can penetrate the skin barrier and moisturize deeply.
However, prolonged usage of strong or harsh surfactants can permanently alter the cell structure of your skin surface. This can damage your skin&#;s barrier function and cause inflamed skin.
Depending on the net charge upon dissolution, surfactants can affect the pH at your skin surface. [5] Products with high pH levels can make your skin dry and itchy, and cause acne breakouts.
Use formulations with an optimally balanced pH. Temporary usage of mildly acidic cleansers can help you reduce acne breakouts. If you have eczema or dermatitis, slightly alkaline cleansers can help.
Wrapping Up
There is no way we can do without surfactants in our daily lives. Whether washing dishes, cleansing your face or doing a load of laundry, surfactants make cleaners work better. Thus, the safest option is to be aware of the surfactants present in the products you use regularly. Try and use the milder versions whenever possible. Also, try buying products from manufacturers, who consciously declare their products to be free of harsh chemicals like SLS and parabens.
Begin By Knowing Your Skin
Let&#;s learn about cleansers and surfactants!
Cleansers work via a class of ingredients called surfactants (that stands for surface active agents).
Surfactants are long, two-headed molecules. One head is hydrophilic, meaning it&#;s drawn to water, and the other end is lipophilic, or drawn to oil. As you know, water and oil don&#;t play nice, but cleansing means we need them to so we can clean off grime and rinse it away. This two-headed molecule serves as a bridge between water and oil: one side binds to a water molecule, the other side bonds to an oil molecule, and presto change-o, water and oil are suddenly friends.
Sometimes, surfactants are used as detergents (bubbly, foaming, cleansing-focused ingredients), and sometimes they&#;re used as emulsifiers (non-foaming ingredients that make oil and water play nice within a formulation &#; for example, creams and lotions, or oil cleansers that rinse off cleanly with water).
There are four types of surfactants: anionic, cationic, amphoteric, and non-ionic.
According to this study, &#;the order of surfactant potential for SC [stratum corneum] alteration and skin irritation is cationic=anionic>amphoteric>nonionic.&#; Translated, that means cationic and anionic are the most likely to irritate your skin and disrupt your moisture barrier; amphoteric is less likely; and non-ionic is the least likely. Of course, this varies widely surfactant-by-surfactant, but it&#;s a good general rule of thumb.
As you may remember from high school chem, an anion is a negatively-charged molecule (with more electrons than protons). Anionic surfactants have a strong negative charge, which makes them extremely effective cleansers, but they can also be harsh.
The most common anionic surfactant is soap. Others you might recognize are sodium lauryl sulfate (SLS) and sodium laureth sulfate (SLES). Speaking generally, anionic surfactants lather well and make lots of foam, and also have a higher incidence of irritation.
Fun fact: you know that tight feeling your skin can get after cleansing? There are three reasons for that:
Boo, SLS.
The opposite of anionic, cationic surfactants have a positive charge. (For all of these surfactants, the charge is held on the hydrophilic side; the lipophilic side doesn&#;t have a charge.)
Cationic detergents are very effective but extremely harsh, so you see them more in household cleaners than facial cleansers. Common ingredients are benzalkonium chloride and cetrimonium bromide. Cationic surfactants do have antimicrobial properties, so you&#;ll sometimes see them in medical or prescription cleansers.
Cationic emulsifiers are much more common in beauty products. They&#;re a fundamental part of hair conditioners &#; they bond to your negatively-charged hair follicle, and they&#;re why your hair stays soft even after you rinse out the conditioner. They appear in skincare products, too &#; you might see them as anything with the suffix &#;-quat&#;.
Amphoteric surfactants have both positive and negative charge &#; their final charge depends on the pH they&#;re in.
These guys are milder and less irritating than the single-charge surfactant types above, so they&#;re popular in facial cleansers and gentle shampoos. The downside is that they foam less. Common amphoteric surfactants are cocoamidpropyl betaine and sodium cocoamphoacetate.
Some surfactants display no charge whatsoever, and we call those non-ionic. Similar to cationic, non-ionic detergents are often very harsh and we rarely see them in skincare.
Where we see them all over the place is as emulsifiers: the polysorbates, the sorbitans, the PEGs, and the laureth-[number]s, to name a few. The vast majority of emulsifiers are non-ionic, so we see these all the time.
Let&#;s refresh. We&#;ve got four types of surfactants: anionic, cationic, amphoteric, and non-ionic. In terms of foaming detergents, we really only see anionic (more harsh) and amphoteric (less harsh) in facial cleansers; for emulsifiers, we see cationic and non-ionic all over the place.
Now that we know what might be going into our cleansers, let&#;s take a look at the three major types of cleansers on the market.
Soap is one of the oldest personal care products in human history. It&#;s made by combining a plant or animal oil with a highly alkaline ingredient like lye (sodium hydroxide). That alkaline ingredient is crucial to the soap-making process, and it&#;s why cleansers tend to have high pHs &#; around 9.0-10.5. Since your skin is naturally slightly acidic, high pH products can disrupt your skin's healthy function and create a whole host of issues.
Soaps foam up well, as we&#;ve all experienced, and they strip off every bit of oil and grease they come in contact with. That&#;s good for dishes, but not as good for your delicate facial skin, which needs the protective, moisturizing oil it produces. Soaps can also strip away your beneficial flora and wreak general havoc on your skin.
Soaps have a lot of strikes against them. I award them zero points as a facial cleanser.
Synthetic cleansers (also called synthetic detergents, or syndets) mix anionic and/or amphoteric surfactants with a number of other mild ingredients to create a gentler cleanser than soap can offer.
In general, these are formulated to have a low pH (between 5 and 7). Usually they don&#;t foam up as much as soap-based cleansers, but they&#;re much, much better for your skin. They leave more of your skin&#;s beneficial oil and flora in place, and penetrate your skin less to disrupt its natural structure. These types of cleansers are ideal for people with normal to oily skin.
Also known as soap-free liquid cleansers, these products don&#;t foam at all. Our whole lives, we&#;re told that it&#;s the foam that gets us clean, so it can feel like these aren&#;t doing their job. Then again, we&#;re also told that oil is bad for our skin and that tight, squeaky-clean feeling is good, so sometimes common wisdom is exceptionally wrong.
Liquid cleansers rely on emulsifier-type surfactants rather than their detergent brethren. Remember from the beginning of the post that emulsifiers are those quiet, peaceful ingredients that allow oil and water to mix in things like lotions and creams. In this case, those emulsifiers are mixing the oil on your face with the water you&#;re cleansing with &#; same as detergents, except these don&#;t foam at all and are much, much gentler.
These are great for people with dry or sensitive skin. Dry skin underproduces oil, so needs to hang on to as much of it as possible, and liquid cleansers remove much less of that oil than their foaming compatriots. Liquid cleansers also have a lower risk of irritation and keep your moisture barrier in tip-top shape &#; perfect for sensitive-skin folks or people with rosacea.
Cleansers are the hardest product to infer anything about from their ingredients lists. There are hundreds and hundreds of types of surfactants, and they all behave differently. Manufacturers rarely announce the pH of their products. Formulation is incredibly important in cleansers &#; even the right ingredients can destroy your moisture barrier if formulated poorly.
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