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Once cast as the harsh antagonist of personal care, sulfates have long been avoided in favor of “gentler” or "cleaner" alternatives. The reality is far more complex. In this blog post, we trace the origins of the sulfate-free movement, explore the nuanced science behind different sulfate types, and consider how thoughtful formulation can shift the narrative. For those interested in the intersection of clean beauty, chemistry, and environmental responsibility, this is an invitation to look deeper.
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The Story Behind ‘Sulfate Free’
The ‘free from sulfates’ marketing movement has its roots in haircare when, in 2001, Purology founder Jim Markham sought to establish unique positioning for his new line of color care shampoos. The idea was that ‘harshness’ associated with sulfates, specifically Sodium Lauryl Sulfate, was stripping hair of both color and moisture. Due to its success, other brands began to emulate the claim and expand into categories outside of shampoos. The notion that all sulfates are harsh by definition became rooted in the customer’s consciousness.
Interestingly, this position was not without basis. Sodium Lauryl Sulfate was invented during World War II as an engine degreaser and post-war became extremely popular as companies shifted production away from military to civilian (and agricultural) use. From the 1940s to the late 1990s, SLS was often used in high amounts due to its big fluffy foam and excellent cleaning properties (as well as low cost). There were plenty of instances where this was taken too far—particularly in ‘budget’ products which may have featured SLS exclusively as a cleaning agent and caused skin and hair to be dry (from a little too much clean).
Are Sulfates Bad for Hair and Skin?
No, not by default. It depends heavily on how they are formulated (specifically how much appears in a formula) and which sulfates are used. There are a few sulfate types all with different profiles. Additionally, we have learned a lot about how to formulate surfactant systems since the 1940s. There are many ways to harness the foam and cleaning benefits of sulfates and mitigate (or eliminate) their harshness by including them at low levels in combination with other surfactant types and conditioning agents.
This is a similar truth explored in Traditional Soap vs. Modern Cleansers, where we look at how cleansing systems are about balance, not absolutes.
There is a recent trend talking about this specifically and seeking to redeem sulfates from their state of disgrace. The Ordinary (Deciem) rolled out a 4% Sulfate Shampoo in 2022 and took the position of pro-sulfate in several op-eds.
At the end of the day, a skilled formulator can work with sulfates in a surfactant system and create a mild effective cleanser. Not all formulas can be painted with the same brush and it’s important to avoid making narrow, monolithic generalizations about sulfates without taking into account the nuances of their role in formulas.
Not All Sulfates are Equal: A Review of Types of Sulfates
There are two main classes of sulfates: Alkyl Sulfates and Alkyl Ether Sulfates. Both Sodium Lauryl Sulfate & Sodium Coco Sulfate are Alkyl Sulfates. Alkyl Ether Sulfates are differentiated by an ethylene processing step which generally puts an ‘E’ in their acronyms. For example: SLES or Sodium Laureth Sulfate (also referred to as Sodium Lauryl Ether Sulfate).
Generally speaking, the order of harshness (detergency) is as follows (assuming a 1:1 comparison of each type):
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Most Gentle: SLES (Sodium Laureth Sulfate)
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Mid: Sodium Coco Sulfate (SCS)
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Strongest: Sodium Lauryl Sulfate (SLS)
Sodium Coco Sulfate (SCS) is believed to be more mild than Sodium Lauryl Sulfate with one study finding the skin irritation potential (zein value) to be 15% lower compared to SLS. The broader range of fatty acids in SCS can lead to larger micelle formation, which may not penetrate the skin as easily as the smaller micelles formed by SLS, potentially reducing the potential for skin irritation.
Are Sulfates Natural or Synthetic?
A little bit of both, with significant variance by both material and manufacturer. Sulfates are often referred to as synthetic due to petrochemical components used in their manufacturing. However, they can be of full or partial natural origin making them either hybrid materials or 100% synthetic origin. It is a confusing grey area that often gets overlooked in the quest to oversimplify this complicated space.
The Environmental Fate & Impact of Sulfates
The interesting and unique aspect of body washes, shampoos, and soaps is that their time of use is very short and most of the product is washed down the drain and either into sewers on the way to wastewater treatment plants (WWTPs) or into septic tanks. This makes their post-use footprint important to understand.
It is also worth noting that body washes and shampoos are not the primary source of sulfates or any surfactant in wastewater. Agriculture and industry are the core contributors to sulfate presence in waterways. Within the household, personal care use also ranks below other cleansers, particularly dish and clothing detergents.
We’ve written more about why natural ≠ safe, where even familiar plant materials face restrictions.
Most major sulfates, including Sodium Coco Sulfate and Sodium Lauryl Sulfate, are highly biodegradable achieving >90% degradation within 28 days. Some data suggests that most WWTP's successfully remove greater than 95% of sulfates from wastewater.
That said, this is an area under continued study, and one we watch closely as formulators.
Surfactant Selection: A Three Part Approach
There are three critical considerations for surfactant selection:
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Origin Material & Processing
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Mildness / Detergency
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Post-Use Footprint
Given the complexities of their production, use and environmental impact, selecting a sulfate (or any surfactant for that matter) for use in formulas is a complicated process and not to be taken lightly.
At Society Botanica, we use Sodium Coco Sulfate in our Cedar & Mandarin Body Wash for its natural origin (coconut), mild profile when formulated correctly, and respectful post-consumer footprint. In combination with other surfactants, it produces a beautiful foam and gentle cleanse.
Pair it with our Cedar & Mandarin Body Lotion for a complete daily care routine — balancing science, sustainability, and sensory pleasure.
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