If you’ve been here for a while, you know surfactants are one of the ingredients that makes it hard to find an effective clean hair shampoo, especially a clarifying one that works with hard water. So in this next research project, I’ve taken on a deep dive into surfactants to help us make better, informed choices!

Just like quats, lumping all surfactants together makes it hard to make practical choices. In this guide we will walk through what surfactants are, how they work, potential safety concerns, and how to evaluate the most common surfactants used in skincare and haircare. We will also review over 30 surfactants and see which ones win “best choice”. Let’s go!

A big thank you to Keith Cretal, Owner and R&D Director of Summit Formulations, a cosmetic manufacturing company based in Boise Idaho for his professional commentary and assistance with this research. 

TL;DR: We prefer non-petro, non-ethoxylated surfactants with low irritation potential and lower environmental concern. There are actually quite a few good options, noted on the list below with a "✅".

What Is a Surfactant?

If you have ever used a cleanser, shampoo, body wash, or micellar water, you have used a surfactant. Surfactants are the ingredients that make cleansing possible. 

A surfactant is short for surface active agent. These molecules reduce the surface tension between oil and water, allowing them to mix. (source)

Oil and water normally repel each other. Surfactants solve this problem by having two parts:

• A water-loving head (hydrophilic)
• An oil-loving tail (lipophilic)

When applied to the skin or hair, surfactants surround oils, dirt, and debris and allow them to be rinsed away with water, which is extremely useful for hair shampoos, household cleaners, and facial cleansers. 

Nearly every product you have that creates some sort of suds or foam, likely has a surfactant. Surfactants are present in many products you use daily, such as:

• Facial cleansers
• Shampoos
• Body washes
• Makeup removers
• Toothpaste
• Laundry detergent
• Household cleaners

Surfactants vs. Soap

All soaps are surfactants, but not all surfactants are soaps. Soap is created through a different process called saponification, a reaction between fats or oils and an alkaline substance such as sodium hydroxide/lye.

While soap also cleanses, it has some drawbacks to more modern surfactants, such as:

• Soap loses effectiveness in "hard" water (high mineral content), leaving residue. Surfactants are specifically engineered to remain effective in hard water.

• Soap has a naturally high pH, typically around pH 9–10. Healthy skin has a slightly acidic surface, usually pH 4.5–5.5. Because of this mismatch, frequent use of traditional soap can disrupt the skin barrier and increase transepidermal water loss. (source)

From Keith Cretal of Summit Formulations

One nuance worth mentioning is that not all synthetic surfactants are inherently milder than soap. Surfactant mildness depends heavily on surfactant selection, concentration, formulation pH, co-surfactants, lipid content, and overall system design. Some poorly formulated synthetic cleansers can be more irritating than a well-made traditional soap.

Now I personally love a good soap, and it’s so easy to find non-toxic soaps out there, but it does need to be part of a broader skincare plan. Soap users should ensure they are hydrating their skin in other ways and preventing TEWL by locking in moisture. (Pssst. Ageless Body Dew is perfect for that). Soaps, such as castile soap, are also fantastic for home cleaning. 

However, in hair care, I always advise against using soap. If you’ve ever experienced build up from using natural soap shampoos, then you know exactly why I caution against them! There are a lucky few whom it seems to work for (if you have very soft water). But for most of us, soap is a hard no for hair care.

I did not include soaps in the comparison chart.

What About Sulfates?

There’s no doubt you have encountered the term “sulfate-free” in hair care and personal care product marketing.

The concern around sulfates in hair and personal care comes from the fact that they are strong cleansing surfactants (like SLS and SLES) that can be too effective at removing oil. 

While this makes them excellent at cleaning buildup in hair care, it can also strip the hair and scalp of natural oils, leading to dryness, frizz, increased fragility over time and hair loss.

In skin cleansers, it can also strip natural oils and lead to dryness which exposes your skin barrier to irritation and other skin conditions. SLS increases transepidermal water loss (TEWL).

How Do Surfactants Differ?

Surfactants can vary greatly in their molecular structure, manufacturing process, and biodegradability. All of these variables can contribute to differences in foaming behavior, skin irritation potential, and environmental impact. Let’s dive deeper.

Molecular Structure

There are four main categories of surfactants, which refer to the molecular structure. 

• Anionic surfactants - These carry a negative charge and are typically the strongest cleansers. These are usually the primary cleansing agents in products because they offer the most cleanse. Examples include:
  • Sodium lauryl sulfate
  • Sodium laureth sulfate
  • Sodium cocoyl isethionate
  • Sodium lauroyl sarcosinate
  • Sodium cocoyl glutamate
• Amphoteric surfactants - These can carry either a positive or negative charge depending on pH. Examples include:
  • Cocamidopropyl betaine
  • Coco betaine
  • Sodium cocoamphoacetate
• Nonionic surfactants - These carry no charge and are generally among the mildest options. They are more commonly used as secondary cleansers, in combination with an anionic surfactant, but can also be used on their own.
  • Decyl glucoside
  • Coco glucoside
  • Lauryl glucoside
  • Caprylyl glucoside
• Cationic surfactants - These carry a positive charge and are mainly used as conditioning agents rather than cleansers.These are found mostly in conditioners and hair treatments. The examples noted below are also quats! (which you might recall from our quats research article). Quats are nitrogen-containing molecules with a permanent positive charge, which is why they behave as cationic surfactants.
  • Behentrimonium chloride
  • Cetrimonium chloride

The molecular structure can help inform the ingredient’s best use cases. But alone, it tells us very little about its safety profile. 

How Surfactants Are Made

Surfactants also differ in where they come from and how they are manufactured. Some surfactants are derived from plant-based raw materials, typically fatty acids from coconut or palm oils, or sugars from corn and glucose. These ingredients are often used to create milder surfactants such as glucosides and glutamates, which are commonly found in facial cleansers, baby washes, and other gentle formulas.

Other surfactants are derived from petrochemical feedstocks. While these ingredients can still function effectively, many consumers (like me!) who follow clean living standards prefer plant-derived alternatives.

Another important distinction is how the surfactant is manufactured. Some surfactants are produced through a chemical process called ethoxylation. This process uses ethylene oxide to modify the molecule and improve its solubility or cleansing performance. We don’t allow ethoxylated ingredients at Ivy & Fields.

For those pursuing stricter clean living standards, ethoxylated ingredients are often avoided because the manufacturing process can introduce trace contaminants such as ethylene oxide and 1,4-dioxane, both of which have been identified as potential carcinogens (that’s why it’s on our no-no list). We also avoid PEG, laureth, and polysorbates, which often indicate ethoxylation.

Biodegradability

Lastly, surfactants vary in their biodegradability. Some break down relatively quickly once they enter wastewater systems, while others persist longer in the environment.

Surfactants that degrade slowly can accumulate in waterways and may pose risks to aquatic life. Biodegradability also affects how easily these compounds can be removed at your municipal water treatment plant. (Remember my post on PVA? It’s a burden to our water treatment centers, and they are often unable to filter it all).

Sugar-derived or amino-acid-based surfactants are usually more biodegradable. 

Environmental and Human Health Concerns

Below are some of the major concerns surrounding surfactants and why it’s important to make better choices in this ingredient category:

Skin Irritation and Barrier Disruption

The most common issue with surfactants is skin irritation.

Stronger surfactants can interact with skin proteins and lipids, which may lead to dryness,  irritation, compromised skin barrier, increased sensitivity, and even hair loss.

This is why Sodium lauryl sulfate is often used in dermatology research as a benchmark irritant because of its ability to disrupt skin barrier function (source).

Allergic Reactions

Certain surfactants can trigger allergic contact dermatitis in sensitive individuals.

A well known example is cocamidopropyl betaine, which has been linked to allergic reactions due to impurities such as amidoamine and dimethylaminopropylamine formed during manufacturing (source)

Contaminant Concerns

As previously mentioned, some surfactants are produced through ethoxylation, a process that can leave trace contaminants such as 1,4-dioxane and ethylene oxide. These contaminants are considered probable human carcinogens.

Ethoxylated ingredients often contain terms like PEG, laureth, polysorbate, or contains -eth somewhere in the ingredient name.

From Keith Cretal of Summit Formulations

Some sulfate and ethoxylated surfactants can still carry a potential risk of trace 1,4-dioxane contamination, but modern manufacturing and purification methods have significantly reduced the issue compared to decades ago.

From a cosmetic chemistry perspective, it’s important to clarify that: 1,4-dioxane is not intentionally added. It is a byproduct that can form during ethoxylation processes

The presence of “PEG,” “-eth,” “laureth,” or “polysorbate” in a name indicates ethoxylation chemistry, but does not automatically indicate unsafe contamination levels in finished products.

It is important to note that the widely use surfactant Sodium Lauryl Sulfate (SLS) is not ethoxylated and is generally not associated with 1,4-dioxane formation from ethoxylation chemistry. However, Sodium Laureth Sulfate (SLES) is ethoxylated.

Other impurities might also be present during manufacturing, such as in the case with cocamidopropyl betaine and amidoamine and dimethylaminopropylamine formed during manufacturing. DMAPA residuals have sensitization effects and lead to contact dermatitis (source).

Environmental Impact

When surfactants enter waterways, they can affect aquatic ecosystems depending on their biodegradability. Older surfactants were known to persist in the environment, but many modern surfactants are designed to be readily biodegradable.

Surfactants that are derived from plant sugars and fatty alcohols tend to degrade relatively quickly in the environment (source).

How to Vet and Compare Surfactants

When evaluating surfactants in skincare or haircare products, here are the factors I believe are worth considering:

• How is it made (this can inform irritation potential and reveal ethoxylation or petro sourcing)
• Skin irritation and allergy potential
• Biodegradability/environmental concerns

I looked at over 30 of the most popular surfactants we see in personal care and home products and compared them side by side on these factors. I also give my recommendation for what I believe to be the best options. 

Practical Comparison of Common Surfactants

Below is a comparison of some widely used surfactants in skincare and haircare. 

My Top Picks For Surfactants

I love doing these research projects, because look how easy it is to make a better choice when ingredients are stacked against each other against certain criteria.

I noted my top picks for preferred surfactants in the chart with ✅ a check mark. Use the following legend: ✅ Preferred 🟡 Conditional ❌ Avoid

This was my criteria:

• I looked for ones made with or derived from plant materials (rather than petro). 
• I did not include any ethoxylated surfactants (including ethoxylated pre-cursors such as Sodium Isethionate). 
• I looked for surfactants that had less environmental concern.
• I looked for low irritation potential (no documented irritation research, DMAPA, etc.). As a 40-year old, I am very concerned with transepidermal water loss and hair loss 🤭–harsh cleansers do not help aging skin or hair!
  • I was actually surprised to find so many low irritation surfactants, so I mostly disregarded the “medium” irritation ones, although, some of those might be okay for those with less sensitive skin/hair types.
    

This research was a lot easier to do than our quats research project. And I was very happy to discover so many good choices beyond the glucosides I had been accustomed to!

Of course, at Ivy & Fields, we only stock products with gentle surfactants. You may be interested in our growing hair care and bath and body collections.

Other Ingredients Still Matter

That said, don't forget to check the rest of the ingredients in a product even if they contain a safe surfactant choice. You will still want to review a product label in full to avoid other concerns like synthetic fragrance, sulfates, parabens, ethoxylates, siloxanes, or harsh preservatives. 

Surfactant Efficacy

Up until now, I have only discussed surfactants from an individual ingredient point of view. But it is important to note that the effectiveness of the surfactant goes beyond a single ingredient. The rest of the formula matters as well. Keith explains.

From Keith Cretal of Summit Formulations

From a cosmetic science perspective, this are good starting criteria, but surfactants should also be evaluated based on how they perform in the full formula, not just whether they are plant-based or non-ethoxylated.

Other important things to consider include:

- How irritating the surfactant is at real-use levels
- Formula pH and skin barrier compatibility
- Hair cuticle swelling and buildup potential
- Eye irritation potential
- Environmental biodegradability and aquatic toxicity
- Supplier quality and contaminant testing
- How the product feels after repeated use

It’s also important to remember:

- “Natural” does not always mean gentler
- “Synthetic” does not always mean harmful
- Ethoxylated surfactants today are often highly purified and tightly controlled

In many cases, the overall formula matters more than any single surfactant ingredient. A well-formulated cleanser with balanced surfactants, proper pH, and moisturizing ingredients can be far gentler than a poorly formulated “natural” product.

I wholeheartedly agree with Keith on this! 

A Note On Product Certifications

Most of my top picks also happen to be ECOCERT/COSMOS approved. (ECOCERT and COSMOS are popular certifications in the EU that require plant origin, no petro, and biodegradability).

Something important to note as it relates to USDA Organic certifications: Most modern surfactants (even natural ones) disqualify a formula from being USDA 100% Organic unless used in very limited quantity under the “Made with Organic Ingredients” category.

USDA Organic certification was never built for cosmetic purposes (it was made for our food system). However, COSMOS and ECOCERT are cosmetic-specific certifications and have criteria especially built for cosmetic review.

These certifications are nice, but I would not say they are required for your products. Many brands do not pursue them simply because of cost.  

Your Turn: Which Are Your Approved Surfactants?

Now that you know a little bit more about surfactants, the question is how will you apply this information to your product choices? 

Personally, when I am scanning ingredient labels for personal use or for consideration to stock at Ivy & Fields, I look for the surfactants I marked with a ✅.

Which were your favorites?