Understanding Ingredients in Cleansers: Surfactants and Sulfates

I just released a couple of posts about cleaning your home naturally and realized there’s a ridiculous amount to say about surfactants, so I decided to chuck it into its own post. Probably no one is really asking any questions about surfactants…

But what you may be curious about is whether some popular ones like sodium lauryl sulfate (SLS) are safe to use. I find that when browsing the ingredient lists of “clean brands,” it can be difficult to always completely understand if all of their ingredients are actually clean. After all, they wouldn’t include ingredients that aren’t clean and call themselves clean, right?

Well, it kind of depends on what they consider clean and what they don’t. To make the whole natural and holistic health journey even more complicated, some ingredient debates are somewhat subjective and people feel differently about them. I think there is some objectivity to what is really harmful and what isn’t, but people go to different extremes to cut certain things out and while some people consider clean just not having toxins, some people say clean is also, for instance, non-irritating.

So where do surfactants fall into this?

Again, most people aren’t even wondering about surfactants. But I do think there are some corners of the internet and some natural living newbies who get hit by this idea that you should be making all your own products and should only use the most naturally occurring ingredients possible. This may lead people to think soap (like true lye soap) and vinegar are their only options.

As I’ve said in my other posts, I don’t think these are the only options. I think there are a lot of great products out there that have minimal and very safe ingredients that go far beyond soap and vinegar. Most of these products include surfactants, so let’s just briefly review that.

What are surfactants?

Are surfactants safe to use?

My research-backed stance on SLS.

Summary / TLDR

What are surfactants?

Surfactants are what I mentioned in our post about natural cleaning when I explained that most hand soaps are actually made of surfactants, not technical soap. When you think of a detergent, think surfactants. Most detergents are a combination of surfactants or at least a surfactant with some other ingredients. Surfactants are just what trap dirt (like soap does) but they also reduce water tension (which soap does not), which is what makes it easier for use with hard water or in applications that need a more smooth rinse. Some can also provide functions such as foaming or thickening.

There are natural and synthetic surfactants and some are toxic and some are not. Some of the surfactants used are definitely not the best, with concerns for negative human and natural systems impacts. However, a lot of surfactants are perfectly fine, especially the ones that tend to be used by “natural” and “clean” brands. 

Both soaps and surfactants are fine options for most applications, but a couple key places you’d probably prefer a detergent/surfactant instead of pure soap is for dishwashing, laundry, and, for some people, hand soap. To understand why, think about pulling a glass out of the dishwasher. If you just use regular soap, it’s going to leave a film. If you use the right surfactants, it should come out crystal clear. 

So are surfactants safe?

Generally speaking, yes, surfactants are safe for use in a range of products. I’m not going to list out all of the surfactants that are safe and the ones that aren’t. Branch basics provides a decent overview on some specific surfactants, though I do find some of their information somewhat inaccurate (e.g., SLS is not banned in the EU completely, it is limited for use in cosmetics and banned for use in food) and obviously has some bias because they’re trying to justify their products, but it is mostly scientifically based and reliable, and they obviously chose their ingredients on purpose. It’s a good exploration.

There are some surfactants to avoid for sure, such as most ethoxylated surfactants, PFAS-containing surfactants, a number of anionic surfactants, and a bunch of other random surfactants. However, most of the surfactants you will see in cleaner brands are going to be certain sulfates like sodium lauryl sulfate (SLS; which some people hate but I will explain I find it safe), sulfoacetates, and alkyl glucosides. These are all great options in my opinion with some being gentler than others. 

It’s also helpful to understand that the ingredients used in body care products tend to be a little different than those used in cleaning products, because they need to perform differently in those areas. For instance, a surfactant that is going to dry your skin out more easily, you probably don’t want in your body wash, but it’s probably fine on your dishes.

There are surfactants I don’t mind in my cleaning products that I don’t like in my personal care products, and that just makes sense. As you may know, I think ingredient context is really important when you’re making purchasing decisions. Not all things are bad all the time. Some things are always bad. But a lot of things are safe, yet not ideal for use in certain contexts. I loveeeee garlic salt in basically every food I ever make, but I’m not going to put it in my coffee… Garlic salt isn’t bad because it doesn’t work in my coffee, it’s just right for some contexts and not for others. You get it.

What about SLS? My stance, based on research.

This is one of those ingredients where you get more into the territory of ideal vs. safe. I’d say this is true of most sulfates, but I’ll talk specifically about SLS.

I consider SLS to be a perfectly safe surfactant for cleaning products and body products. People really like to argue about SLS, though probably not quite as much as they used to. Some people say it’s toxic to humans and the environment. It’s gotten a very bad rap over the last couple decades because at one point concerns were raised that SLS causes cancer. 

I have reviewed the research many times before and found that, though SLS can be somewhat irritating to the skin, there really isn’t any evidence for most of the concerns people spout, and there’s certainly no evidence that SLS or most sulfates cause cancer.

I’d like to add a note that whether or not SLS/sulfates are irritating aren’t really relevant to whether or not they’re safe. Lye soap, very natural and very safe, is irritating to they eyes, mouth, lungs, etc. I mean… so is salt and vinegar and so many perfectly “safe” things. Again, when we talk about irritation, we’re typically getting more into what’s ideal or not versus what’s safe or not.

The SLS debate can be a confusing and misleading conversation to follow, and part of that is because of the age-old problem of people repeating things without first realizing if what they’re repeating is really supported. SLS is a naturally derived surfactant that, when formulated correctly by reputable companies, should not cause any irritation nor any health issues. The only possible concern I have with it is that it could be dangerous for aquatic life, because a problem with anionic surfactants is they don’t degrade super well, but the concern doesn’t seem supported with SLS specifically, as well as some other safe sulfates. 

Some of the confusion I think comes from taking an analysis of the properties of the ingredient, in this case SLS, as direct application for its toxicity without regarding how it’s actually used. Surfactants have an impact on microbiomes, human and non-human. SLS in its raw form dumped onto someone’s body or into a lake would probably have some toxic effect and cause some damage. However, in the concentrations and applications in which it is actually used, there is no evidence of any negative effects. 

Not to make it more confusing, but even though I would consider SLS safe, I would not consider sodium laureth sulfate (SLES) safe. This is mostly because a type of dioxane can be produced during processing as a by-product, and that is toxic to humans and the environment. So no, not all sulfates are safe. 

You’ve got to do some research on individual products when you’re deciding to use them, that’s just what it takes to make good purchasing decisions. 

I’ll just reiterate that though I find most sulfates, including SLS (but not SLES!), to be safe, I don’t use personal care products that use them. They are more likely to cause irritation because they are stronger and cause more drying. As someone with dry skin already, that’s a no for me. Plus, there are other gentler options. Luckily most skin care doesn’t use SLS anymore. But it’s less about toxicity, to me, than it is about function.

If you really just want to try to stick to the gentlest surfactants, even in your cleaning products, one option is to stick with mild alkyl glucosides, like coco glucoside, or sulfoacetates, such as sodium lauryl sulfoacetate SLSA, which is very similar to SLS but gentler. Glucosides are sugar-based surfactants and, though they are considered “synthetic,” this is because they require a bit of processing to get to their surfactant state from, for example, the straight up coconut. I didn’t get into it and am not going to but essentially, a lot of purely synthetic surfactants are not great, while most of the naturally-derived (like from a coconut) synthetic surfactants are very safe and much gentler than purely natural surfactants.

Summary / TLDR

Most surfactants are safe, and even a lot of sulfates, including SLS, are safe. There have been concerns raised about some sulfates that have not stood up to the research. However, while sulfates, specifically, may mostly be safe, they are more ideal in some situations than others. 

Because sulfates, including SLS, are drying and can be irritating, I choose not to use them in products I put on my body. However, I’m fine with them in my cleaning products. They’re irritating because they’re effective at their job of grabbing all of the things and ushering them away in a wash. This is challenging for skin, but great for cleaning my house. 

There are definitely some unsafe sulfates, such as SLES, and unsafe surfactants, such as ethoxylated and PFAS-containing surfactants. You should obviously avoid these. Beyond this, it can be hard to know what is safe and what is not. If you want a resource to help guide you in figuring this out and don’t have the time to individually research every ingredient, the EWG consumer guides are great for this. They provide ratings on toxicity as well as recommended use restrictions. I don’t find it a perfect system and always prefer looking at individual research, but it’s a great starting point, especially if you have limited time. (contrary to what some people have said online, you cannot pay your way into good rankings or becoming EWG verified, that is a myth/rumor that is not true)

If you want to avoid the more irritating surfactants in all your products, including cleaning supplies, there are plenty of options for this. There are milder surfactants, like alkyl glucosides and sulfoacetates, that are gentler and still effective. Branch Basics is a good company if this is the route you want to go, though there are quite a few options.

I hope you found this review helpful and feel more confident in making purchasing decisions for your home. If you enjoyed this content, please consider subscribing to our newsletter and browsing our other blog posts for more information you may enjoy. If you have any questions or topics you’d like me to break down, shoot me an email and let me know.