What are Surfactants and Why are they in my shampoo?
But I love the Soapy Suds
Surfactants are a class of chemical compounds that play a crucial role in many cleaning and personal care products, including shampoos. The term “surfactant” stands for surface-active agent, and these compounds have the ability to alter the properties of surfaces and liquids. Let’s take a look at these surfactants and some other ingredients that might be hidden in our shampoos.
What are surfactants?
Surfactants are compounds that lower the surface tension between two substances, such as between a liquid and a solid or between two liquids. They achieve this by having a molecular structure with both hydrophilic (water-attracting) and hydrophobic (water-repelling) parts. This dual nature allows surfactants to interact with both oil and water, which is essential for effective cleaning.
Types of Surfactants
Surfactants are categorized based on their charge, which affects their behavior and application. The main types include:
Anionic Surfactants:
Charge: Negative
Function:
They are excellent at removing dirt and oil due to their strong cleansing properties.
Examples in Shampoos:
Sodium lauryl sulfate (SLS), sodium laureth sulfate (SLES).
Considerations:
Can be harsh on the skin and hair, potentially causing dryness or irritation, especially in higher concentrations.
Cationic Surfactants:
Charge: Positive
Function:
Often used in conditioners and hair treatments for their conditioning and anti-static properties. They adhere to negatively charged surfaces (like hair) and help smooth and detangle.
Examples in Shampoos:
Behentrimonium chloride, cetyl trimethyl ammonium bromide.
Considerations:
Less commonly used in shampoos but important in conditioning products.
Non-Ionic Surfactants:
Charge: None
Function:
Mild and less likely to irritate. They help to solubilize oils and are often used in combination with other surfactants.
Examples in Shampoos:
Decyl glucoside, caprylyl/capryl glucoside.
Considerations:
Suitable for sensitive skin and often used in gentle or natural formulations.
Amphoteric Surfactants:
Charge: Can be positive or negative depending on the pH of the solution.
Function:
Known for their mildness and ability to provide a creamy lather. They are often used in formulations for sensitive skin.
Examples in Shampoos: Cocamidopropyl betaine, cocamidopropyl hydroxysultaine.
Considerations:
They contribute to the overall mildness and conditioning of the shampoo.
Saftey Concerns
Surfactants are essential components of shampoos, providing effective cleansing, foaming, and emulsifying properties. They help remove oil and dirt, enhance the user experience through lather, and ensure that the shampoo performs as intended. By choosing the right surfactants, formulators can create products that meet the diverse needs of consumers while addressing concerns about skin sensitivity, environmental impact, and overall hair health. But choosing the correct non-toxic one can be hard!
Some surfactants are made from coconuts and while that may sound safe, it can actually be harmful. For instance, cocamide DEA is derived from coconut, but it is on the California Proposition 65 List for causing cancer.
Safer Surfactants you might find in Shampoo
Surfactants to Avoid
Shampoo Ingredients to Avoid
What It Is:
- Coal tar is a byproduct of coal processing and is used in various medical and cosmetic applications.
Why It’s Used:
- Dandruff and Scalp Conditions: Coal tar is primarily used in shampoos for treating dandruff, psoriasis, and seborrheic dermatitis. It works by slowing down the production of skin cells on the scalp, thereby reducing flakiness and itching.
Considerations:
- Coal tar can be irritating to some people and may stain light-colored hair or fabrics. It is also a controversial ingredient due to potential concerns about carcinogenicity in high concentrations.
What It Is:
- Cocamide DEA (Diethanolamine) is a foam-boosting agent derived from coconut oil and diethanolamine.
Why It’s Used:
- Foaming Agent: It helps to create a rich lather, which enhances the user experience during shampooing.
- Thickening Agent: It can also help to thicken the product and improve its texture.
Considerations:
- Cocamide DEA has been associated with potential health risks, including concerns over its potential to form carcinogenic nitrosamines when it reacts with nitrites. Due to these concerns, its use has become less common in formulations.
What They Are:
- Ethoxylated ingredients, such as polyethylene glycol (PEG), are derived from the reaction of ethylene oxide with other substances.
Why They’re Used:
- Emulsifiers and Solubilizers: They help to blend oil and water-based ingredients, improving the consistency of the shampoo and aiding in the effective delivery of active ingredients.
- Conditioning Agents: They can also help to condition and moisturize the hair.
Considerations:
- Ethoxylated ingredients can sometimes be contaminated with 1,4-dioxane, a byproduct of the ethoxylation process that is a potential carcinogen. Manufacturers often work to reduce or eliminate this contaminant.
What They Are:
- Formaldehyde releasers are chemicals that slowly release formaldehyde over time. Examples include quaternium-15, DMDM hydantoin, and imidazolidinyl urea.
Why They’re Used:
- Preservatives: They are used as preservatives to prevent the growth of bacteria, mold, and yeast in shampoos, extending the shelf life of the product.
Considerations:
- Formaldehyde and formaldehyde releasers can cause allergic reactions and skin irritation in some individuals. They are also classified as potential carcinogens, leading to concerns about their safety.
What It Is:
- Fragrance is a blend of various aromatic compounds used to provide a pleasant smell.
Why It’s Used:
- Aesthetic Appeal: Fragrance enhances the sensory experience of using the shampoo, making it more enjoyable for users.
Considerations:
- Fragrances can sometimes cause allergic reactions or sensitivities in some individuals. They are often a mix of many different chemicals, some of which may be potential allergens or irritants.
What It Is:
- Iodopropynyl Butylcarbamate is a preservative used to prevent microbial growth in personal care products.
Why It’s Used:
- Preservative: It helps to keep the shampoo free from bacteria and mold, extending its shelf life.
Considerations:
- It is generally considered safe in low concentrations but can cause allergic reactions or irritation in some people.
What It Is:
- Methylchloroisothiazolinone (MCI) is a synthetic preservative used to prevent microbial contamination.
Why It’s Used:
- Preservative: It helps to extend the shelf life of personal care products by inhibiting bacterial and fungal growth.
Considerations:
- MCI has been linked to allergic reactions and skin sensitivities, particularly with prolonged or repeated exposure. It is often used in combination with methylisothiazolinone.
What It Is:
- Methylisothiazolinone (MIT) is a preservative used to prevent microbial growth.
Why It’s Used:
- Preservative: It serves the same purpose as MCI, protecting products from microbial contamination and extending shelf life.
Considerations:
- MIT is known to cause allergic reactions and skin sensitivities in many people. Its use has been restricted in some regions due to safety concerns.
What It Is:
- Retinyl Palmitate is an ester of retinol (vitamin A) and palmitic acid.
Why It’s Used:
- Anti-Aging and Conditioning: It is used for its antioxidant properties and potential to promote healthy skin. In shampoos, it can help improve scalp health and condition hair.
Considerations:
- Retinyl Palmitate is generally safe but can cause irritation in some people, particularly in higher concentrations. There are also concerns about its stability and potential to cause sensitivity to sunlight.
What It Is:
- Triethanolamine (TEA) is an organic compound used primarily as a pH balancer and emulsifier.
Why It’s Used:
- pH Adjuster and Emulsifier: It helps to maintain the proper pH balance of the shampoo and aids in the blending of oil and water-based ingredients.
Considerations:
- TEA can react with other ingredients to form nitrosamines, which are potential carcinogens. It is used in relatively low concentrations, and its safety is generally considered acceptable when used correctly.
