Thursday, June 7, 2012

Query: Why do you think sulfates are bad for your hair?

Every day I see something where someone says that sulfates are bad for their hair and they won't be using them. Why is this? Why do you think sulfates are bad for your hair? What will sulfates do to your hair if you use them? Who told you that they were bad for your hair?

In the past, I'd see people saying that SLS or sodium lauryl sulfate was bad for our hair, and I wondered why. On a scale of 1 to 10, with a rating of 1 and 2 meaning your surfactant is gentle and a rating of 3 and 4 meaning your surfactant is mild, SLS is a 4.5 to 5 rating, which is still really low compared to the surfactants of the past. And you don't use a surfactant neat on your hair - there are so many ways to increase mildness in a surfactant based product, that just about any blend of foamy, lathery surfactants can be considered to be mild these days.

What about sodium laureth sulfate (SLeS) or ammonium laureth sulfate? What about sodium lauryl ether sulfate? What about alkyl glyceride sulfates? And what about behentrimonium methosulfate? Do you consider all the sulfates in any category of ingredient bad? Why?

A thought...Where did you get the idea that sulfates are drying? And that they are more drying than other foamy, lathery surfactants?

I really want to understand why this is coming up over and over again, so please share with me what you know about this concept and the reasons we aren't supposed to use sulfates on our hair as well as what the impact of using sulfates might be on your hair and scalp. What philosophy or website told you about this idea? What are you using instead of sulfates on your hair? I'd love to hear from you about this!

38 comments:

Brendita said...

Several years ago, I decided that I wanted to limit my and my family’s exposure to harsh chemicals. When I first started my online store, I did a lot of research into plant derived ingredients. During my research, I kept coming upon information about the drying effects of sulphates

Sulphates are detergents that, in addition to breaking up grease & dissolving oils, create lather. A lot of people associate rich, full, thick lather with effective cleaning. Many people also believe that if your cleanser or shampoo doesn’t produce a lot of lather, you’re not really getting your hair or body clean. For that reason, I believe, a lot of shampoos & shower gels use higher amounts of sulphates than are necessary.

My son has had a mild case of eczema since he was a toddler. One of the best ways to alleviate the dry skin that this condition can cause was to eliminate things that are drying to the skin, such as sulphates.

I have afro-textured, color treated hair, which tends to be on the dry side. My skin is also very dry. Using my own sulphate free shampoos has greatly reduced the dryness in my hair and my demi-permanent colors last a lot longer. I only use castile soap (which is naturally sulphate free) in the shower and that has also helped with my former dry skin condition.

It is also a wide held belief that sulphates are responsible for upsetting delicate eco balances when they go down the drain and into the environment, getting into streams and soil.

There are a few sulphate free surfactants that I like: sodium cocopolyglucoside tartrate and sodium cocoamphoacetate. These are in my sulphate free shampoos and facial cleansers.

Thank you for raising such a thought provoking question! I am a new reader of your blog and I am enjoying it very much.

Brendita said...

Oh, sorry! I forgot to mention behentrimonium methosulfate is an AWESOME conditioner. It's not a surfectant (doesn't create lather/bubbles). I am working on a recipe for a conditioner and this will be one of the actives in it.

Alkyl Sulfonate is a pretty strong surfectant, in my opinion. I find it nearly as strong as sodium laureth sulfate, ammonium laureth sulfate and sodium lauryl ether sulfate.

Kim said...

I first heard about sulfate shampoos from the Killer Strands blog. This is what you will see when you go to their online store in the shampoo section :

"You can purchase these shampoos with complete confidence in your purchase, as KillerStrands only carries Sulfate-Free shampoos. I felt after working on 10,000 heads of hair that the ingredient Sodium Lauryl Sulfates or SLS, Sodium Laureth Sulfates – SLES, ALS, and Ammonium Lauryl Sulfates all seemed to be the common denominator part of the problem of the increase in hair thinning and loss in women.

All the ingredients in all shampoos have been reviewed, they are all sulfate-free and have excellent ingredients lists ..so rest easy and shop away, your hair will flourish.

Remember we are not fanatics here at Killer Strands. Just people, trying to have the healthiest head of hair we possibly can.

STEP 1 of 14 of the 10,000HEADS Hair Strengthen System : Sulfate-FREE Shampoo-ONLY"

I've been using ABBA Color Protect shampoo for a couple of years now, and after getting used to the different feel of milder surfactants, I definitely did notice that my hair didn't have that stripped, coarse feeling after washing it, and my highlights don't change tone anymore. It's expensive though, and after reading this blog I think I can make my own, and include what I want to in there.

As an aside, I have not yet made any of my own products, although I have thoroughly enjoyed reading this blog and have learned so much, even about basic chemistry - thanks to you Susan. And. . . I do have some stuff on order and will be in the workshop soon!

Susan Barclay-Nichols said...

Hi Brendita. Behentrimonium methosulfate is a surfactant - a surfactant isn't just something that foams or lathers, it's something that reduces the surface tension between phases. (Click here for more information!) It is a killer conditioner, which is why it is the basis for almost all the conditioners I make!

SLeS and SLES are known to be much milder than SLS. And when the anionic is ammonia, it's milder still. C14-16 olefin sulfonate is considered mild and a great degreaser.

This is what I want to know - where did you get the information that these were considered harsh surfactants? Where did you get the idea they dry out your skin? Don't get me wrong - there are all kinds of gentle to mild lathery, foamy surfactants, and part of the fun in making our own products is that we are free to use the ones we wish, but I'm being inundated by people who are telling me that all sulfates are considered bad and I just don't get it. Can you give me more information on who told you these things?

Brendita said...

Hi Susan. Thanks for the info & correcting my ignorance! I have learned something new today!

The info. that I wrote was from my own experience, not from anything I read or heard.

I noticed a MARKED difference when I stopped using sulphate shampoos in my hair. And when I switched from sulphate shower gels to castile, my skin wasn't dry soon after stepping out of the shower. It used to begin to look ashy as soon as the water evaporated.

When I made my first batch of shampoo, I used Alkyl Sulfonate as the primary surfactant, but it had the same drying effects as SLS & SLeS. Now I use sodium cocopolyglucoside tartrate and sodium cocoamphoacetate for shampoos and facial cleansers with great, non-drying results.

My son's skin also responded in a positive manner to sulphate free castile. He notices an immediate the difference if he uses a sulphate containing shower gel.

Kate McAfee said...

Personally, I LOVE SLS. A few years ago I started having a problem finding a shampoo that would not leave me looking like an oil slick in the middle of the day. This was before I started working with cosmetics. Now that I formulate cosmetics all day long I make my own shampoo with SLS and am so much happier with the appearance of my hair. I am an all over oily person and I hate it. That said- I am not a fan of SLS in hand/ body wash. I wash my hands many many times a day at work and my hands began to get very dry and cracked. I made some new soap for the lab and my hands improved a lot. So anecdotaly, maybe it is drying to some people but I think it's been demonized far too much.

Anonymous said...

Check out the book Curly Girl. The first time I saw sulfates are bad is in that book, right along with silicon compounds are bad. How reliable is she for a reference? In the first edition of this book she said that what products you need depend on your "curl type" or how your hair looks.

After this book came Live Curly, Live Free, which expands the word "sulfates" to include any surfactant that has a name similar to sodium or laurel or sulfate. See this page: http://livecurlylivefree.com/product%20ingredients.htm

It seems to have spread to all the long hair and naturally curly sites on the web.

Heather said...

I stopped using sulphate shampoos when I started getting the Brazilian Blowout a couple years ago. They say the sulphates will cause the treatment to wash out more quickly. It is true. I was on a trip recently and forgot my shampoo and had to use a regular one twice. My curls came back with a fury. Totally sucked since the treatment normally lasts 3-4 months on me.

Before that I used sulphate free products on and off at the recommendation of several hair stylists. I found that the sulphate free shampoos were much gentler, but sometimes I wanted something harsher as my blond hair tends to pick up brassy tones from rust and what not in the tap water. The stripping effects of sulphates seemed to help with this, though my hair was always really dry and crappy feeling.

Anyhow, I live where I don't have excessive rust in the pipes now and I started using No-Poo (hate the name) shampoo. I like it. My hair is very soft and much more manageable. It doesn't have as much body, but that's probably a good thing. I hate it when it's dry and poofy.

Perhaps it all depends on your hair type. I have naturally curly, fine hair- but a lot og it. Personal experience has shown me better results with sulphate-free products.

Mychelle said...

Paula Begoun sent out a newsletter about this same topic just this morning; I was reading it not a moment before I came here! Actually, Paula is where I first learned about sulfates (ingredients in general), though she is very balanced about it. Lauryl is more drying than laureth so go with laureth was the basic message. I have very long, thick, processed hair and I only use shampoo with lauryl sulfate when I need to clarify (styling products plus well water equals build-up on occasion). My personal experience has taught me that sodium lauryl sulfate is indeed more drying, though these days we really only see this ingredient used in shampoos touted as "clarifying" or "volumizing" so the overall formulation is a part of that. In my shampoo I stick to more gentle surfactants such as SCI, CAPB, DLSS, etc. I do use a touch of sodium coco sulfate for bubbles, so I'm not on the sulfate-free bandwagon by any means. And I have also heard it is not as environmentally friendly as other surfactant options, and that is important to me. While I do believe there is a lot of hype about sulfates, I think there are definitely better surfs out there! Though I am always trying to educate people on the difference between lauryl and laureth. Like many ingredients sulfates have been demonized, but I agree that this is not the best surf for hair.

Clive said...

I've been experimenting with ALS (ammonium lauryl sulphate) and find it makes a shampoo that is noticeably milder, leaves the hair softer. (Blended with sodium cocoamphoacetate and cocoamidopropyl betaine).
However it is quite expensive and so I've decided to go to newer surfactants such as Plantapon LG Sorb.

anja said...

I definitely can't speak for anyone else, but SLS (or at least the SLS-containing shampoos I've used) makes my scalp itch. Other sulfates don't seem to be any problem.
So, I don't think that sulfates in general are bad for my hair; I just think that SLS in specific is bad for my scalp. I think there are probably others with certain allergies or sensitivities who just like to play it super-safe.

Organa said...

Hello Susan, I am Brazilian and I found many useful information here in your blog, not long ago that I started to formulate cosmetic products, or am just a learner yet, but the little time I have learned a few things in formulating practices. First was working with SLS and SLES 27% pure, now bought ALES, in the beginning they resected my hair, but after awhile I realized that much depended on the concentration of the surfactants should use a maximum of 15% and that's worked well, now that I'm seeing people do not want to use shampoo with sulfates (perhaps because of dioxane?), is simple and only use shampoos for children most are made ​​with coco glucoside and derivatives thereof, except that I think the hair grease of adults would not be child removed by a shampoo, but good anyway. I used Varisoft BTMS pellets from Evonik and liked the results on the hair, but I think it affects the use gradually from the third day of use, I'm still learning to make as I said but I think everything is exaggerated may not be good hair. Speaking of what you think of this formulation 1% pure SLS, SLES 8%, 6% ALES, Cocamide DEA 3% propyl betaine Coco starch 2%, Poliquartenium 10 1%, 1% Dimethicone, Cetyl alcohol 0.5%, glycol distearate 1.5% CMC 0.5% Preservative 0.5% glucamate donate 0,5% Fragrance 0,5%.

Organa said...

Hello Susan, I am Brazilian and I found many useful information here in your blog, not long ago that I started to formulate cosmetic products, or am just a learner yet, but the little time I have learned a few things in formulating practices. First was working with SLS and SLES 27% pure, now bought ALES, in the beginning they resected my hair, but after awhile I realized that much depended on the concentration of the surfactants should use a maximum of 15% and that's worked well, now that I'm seeing people do not want to use shampoo with sulfates (perhaps because of dioxane?), is simple and only use shampoos for children most are made ​​with coco glucoside and derivatives thereof, except that I think the hair grease of adults would not be child removed by a shampoo, but good anyway. I used Varisoft BTMS pellets from Evonik and liked the results on the hair, but I think it affects the use gradually from the third day of use, I'm still learning to make as I said but I think everything is exaggerated may not be good hair. Speaking of what you think of this formulation 1% pure SLS, SLES 8%, 6% ALES, Cocamide DEA 3% propyl betaine Coco starch 2%, Poliquartenium 10 1%, 1% Dimethicone, Cetyl alcohol 0.5%, glycol distearate 1.5% CMC 0.5% Preservative 0.5% glucamate donate 0,5% Fragrance 0,5%.

Clive said...

anja is right, I also found SLS makes the scalp itch. But what else should we expect from a surfactant that is made for cleaning car engines and industrial premises?

LabMuffin said...

Sulfate-FREE shampoos make my scalp itch! I'm oily and need a good surfactant.

My mum had a freak-out about a chain email that went on about what Clive said above - SLS is used as an industrial cleaner and therefore is bad. I told her that oxygen is super-reactive and is the biggest cause of oxidative damage, and she should stop breathing to reduce the cancer risk :P Chain emails tend to have a lot of unreliable info, and SLS is a target in at least one...

Robert said...

The Zein test is an attempt to quantify the mildness and irritation potential of different types of surfactant classes.

The Zein values of different surfactacts may be found on Page 3 at the following link:

www.essentialingredients.com/pdf/ClariantMildSurfactants.pdf

Anonymous said...

Its the "natural" trying to use scare tactics so that you will buy their product over what you are currently using. you can't believe a lot of these hoaxes that are going around that are based on no science. Its annoying. - Dean.

Nancy Liedel said...

I'm not scared of surfactants. I have oily hair and by golly, I adore them. I would have been an oily, fugly mess in the days before the daily shower.

My personal shampoo bar has SLS in it. GASP!!!!!!!!!!!!!! I don't sell that one, but it's very nice. It's in combination with others. I don't let slow news days ruin my work. I make a good and safe, most important, product and if it can't get into Whole Foods? Life goes on.

So there.

Rant off. Soapbox is now free for use for anyone else.

Kirk said...

There's are a couple data points that are conspicuously missing from the discussions about SL*S and other sulfates.

First, what is the level of oil production in the people who were the de facto test subjects?

And concurrent with that, what was the frequency of use of the product?

If substance A is simply more effective at wash oils away than substance B, and/or the ingredients that are applied with B contribute more of a persistent after-wash moisturizing or film forming behavior than A, then substance A will have a greater likelihood of stripping away sufficient oils to be perceived as drying.

Concomitant with that is the second question. How often are the products being used? For each individual person, there is going to be a threshold that is a combination of the effectiveness of the product at removing oils, the after-washing moisturizing or film forming behavior, the level of personal oil production, and the frequency of use that determines whether the use of the product is effectively "drying" or not.

My conjecture is that SLS and friends are more effective at removing oils than are some other commonly used alternatives, that the common over-the-counter products that use them tend to not pay much attention to the after-washing moisturizing/filming behavior, and that the people who seem most afflicted with complaints about sulfates tend to have a combination of personal oil production and frequency of use that combines with the above factors to produce the perception that sulfates themselves are drying, when in fact it's a collection of factors that are causing the drying effects.

Switching to alternative products which are less effective oil removers, and/or more effective after-wash moisturizers/filmers alters a couple variables in the equation, and produces a difference result, and the tendency is simply that those variable changes tend to come into play more with products that don't use SLS and friends.

Susan Barclay-Nichols said...

Hi Kirk! Are you arguing that one's perceptions of how SLS works for them is directly related to their oil production and the quality of the products they might have tried? That the sensation of dryness and itchiness might be related to things other than the use of SLS?

I think I address that in this post - what causes that feeling of tightness after washing? and in other posts in my surfactant series.

I don't think those points were missing in this post or this discussion: This post was about personal opinions of sulfates and where information about sulfates was found. I asked that question to gather information for future blog posts. I think we should ask ourselves what our skin/hair type might be and make decisions about what surfactants might work best with that type, but I've written about that to death, it seems! This wasn't that kind of post. But I appreciate your input.

Kirk said...

Susan, yes, I am. Because it seems that almost every individual's argument about why sulfates are bad boils down to those personal anecdotes, or hearsay from other people's personal anecdotes.

I have yet to see a cogent scientific argument for why sulfates, as a general group of compounds, are bad for hair. I've done some looking, and everything that I have found matches the arguments that are in this thread. It's all FUD and anecdote.

Thanks!

Вера Смирнова said...

Indeed, SLS is itching for a small percentage of people.This is a dermatological fact. This is another horror story that love to repeat sellers of expensive shampoos: DONT BY SLS! IT IS ITCHING!
My answer: yes. but not for me and not for everyone.

behentrimonium methosulfate are bubbling in my shower!!!! (I use solid conditioner)

Bajan Lily said...

I wanted to share this article on surfactants showing that some of the things we think are mild can be almost as harsh as SLS. I like this lady because she tries to give science without taking sides. http://www.thenaturalhavenbloom.com/2012/06/are-sulfate-free-shampoos-really.html?m=1

piggy said...

Alternating treatments with anionic and cationic surfactants have been demonstrated to form insoluble complexes on the hair. In the case of damaged hair, these insoluble complexes can deposit beneath the hair cuticle and cause scale lifting, which leads to greater incidence of cuticle fragmentation. Dodecyl alcohol sulfates (like SLS & ALS) in particular have been shown to be very effective at producing scale lifting. (Source: Chemical and Physical Behavior of Human Hair, 4th Ed.)

On an unrelated note, many commonly used shampoo surfactants (not just sulfates) are potentially drying to the hair. Over time, repeated shampooing can remove structural free-lipids from the cell membrane complex, which raises hair's isoelectric point and decreases its hydrophobicity. (Source: "The Cell Membrane Complex: Three related but different cellular cohesion components of mammalian hair fibers" J. Cosmet. Sci., 60, 437-465, July/August 2009)

Sara @Osmosis said...

I decided to try sulfate free after noticing a difference at how my hair reacted to SLS and ALS. ALS being milder seemed to keep my hair cleaner longer. It seemed like my scalp produced more oil after using SLS shampoos. When I switched to sulfate free shampoo I got an extra day out of my hair before it became super greasy. I'm still learning about all the surfactants they use in the sulfate free shampoos. Some of those are better than others for my hair. I haven't narrowed it down yet, but when I do I'll be ready to try formulating my own.

Purple Rain said...

I first heard about SLS being 'evil' when I stumbled upon a dermatology book that focused on disorders of African skin. It said that SLS is a known irritant depending on the amount and that African skin is more susceptible to drying and irritation from SLS. This is in comparison to Caucasian skin. Black people love lotions and I assume its a combination of using SLS in products and not living in humid environments. I also assumed that the level of SLS in commercial products is acceptable because it was tested on Caucasian skin and found not to be too irritating but on African skin it can be too much.

I tried to find an article about it and I found one from 1988. I dont know if there are any more recent studies

http://crowndiamond.net/techpack/0527.pdf

________
Personal Anecdotes

SLS shampoos leave my hair hard, dry,crunchy and difficult to manage. But they do of course leave my scalp and hair squeaky clean.

In terms of body wash, SLS ones leave my skin dry and itchy almost immediately. It's like a sprint from the shower to the lotion bottle to fight the itch. Especially in the winter the itch is unbearable. I've broken skin and caused rashes from scratching my skin in the evenings. The solution for me has been to switch to a non-SLS body wash. I use Burt's Bees now. I see it has "Decyl Glucoside" I don't know where it lies on the harshness scale, but my skin is happy.

Anonymous said...

Hi,

You ladies seem really knowledgeable, so sorry if this is off topic, but I have been searching and can't find an answer to my question.

I got a Brazilian blowout ( I know, never again! ) a while back and just recently started doing water only washing. I need a little clean in my life, so I was hoping to use peppermint castile bar soap or watered down castile liquid soap. Is this Brazilian blowout safe? I know it doesn't have sulfate, but it has sodium hydroxide, is this safe for BB hair? It says there is no more left after "saponifying"

Bar soap ingrdients below and liquid castile ingredients following.

BAR:
Organic Coconut Oil*, Organic Palm Oil*, Sodium Hydroxide**, Water, Mentha Arvensis*, Organic Olive Oil*, Organic Hemp Oil, Organic Jojoba Oil, Organic Peppermint Oil*, Salt, Citric Acid, Tocopherol
* CERTIFIED FAIR TRADE INGREDIENTS
** None remains after saponifying oils into soap and glycerin

LIQUID:
Water, Organic Coconut Oil*, Potassium Hydroxide**, Organic Olive Oil*, Mentha Arvensis*, Organic Hemp Oil, Organic Jojoba Oil, Organic Peppermint Oil*, Citric Acid, Tocopherol

Alexis said...

I believe that much of the concern with sulfates began around 2006 because of an article in Allergy & Asthma that was written by a mother who "cured" her son's eczema by switching from detergents to saponified soaps for every cleanser used in her house. Her website is solveeczema.org.

I followed her method for several years, but started to switch to other cleansers because I read on her site that the molecule size of the detergent was a big factor in how irritating it is to skin, plus it was getting increasingly difficult to wash my daughter's hair and my hair with cp soap. Also within her own reporting of her research into studies, she mentioned that SLS was used in lotions to help actives get into cells, but this was not as irritating as washing with detergents. This comparison just nagged at me.

My highly unscientific belief is that there is a connection, just not the one she thinks! Our immune systems are incredibly complicated, and most things we do treat symptoms rather than cure diseases. I can think of only a few diseases that have a decent degree of reversibility, and the treatment for those seems to be the same: diet and exercise!

I don't mean to criticize what she does because I can assure you from my own experiences that it is heart breaking to see your child with a red, painful rash that no medication helps, but I also know from my own experiences that it just isn't that simple either.

A.J. Lumsdaine said...

Hi Alexis,
I'm the mom who wrote the SolveEczema site. I'm sorry to hear you didn't find a good soap-based shampoo for your hair. Sometimes the problem is hard water, though there are workarounds for that. My own soap-based shampoo works as well as the detergent-based one I used to use, and my skin is less dry.

I wish I could take credit for having such a profound impact on product choices, but there's actually quite a bit of dermatological research demonstrating how irritating SLS is, especially for those with eczema. I didn't write that article in Allergy & Asthma Today, they contacted me for an interview, and did a wonderful job covering a complex issue in a short space.

That's an interesting take on the site perspective, but it's really not accurate, I'm sorry to say, it's not even very close. For example, I do not recommend lotions that penetrate or have SLS in them, nor do I concur with the industry practice of putting detergents in lotions to help them penetrate the skin, I recommend only what I call "barrier moisturizers".

As the site gets used by more and more people, I'm seeing more and more interesting but sometimes even opposite interpretations. All I can do is my best to explain. I'm trying to rewrite the information in a book, so hopefully it will explain it better, but ultimately the goal is a medical study and publication. There is a video now, which is about 45 minutes long and only a few slides, that may help. The video links from the home page.

The basic issue is that modern syndets are dramatically more hydrophilic (attracted to water) than soaps. Because of the hydrophilic properties, syndets affect the permeability of the skin in unprecedented ways, resulting in excessive water loss and dryness over time. They also directly affect penetration of antigen in the skin, which impacts the immune system especially for infants. Sodium lauryl sulfate is a particular problem, because it is a biological analog of a natural surfactant human beings make in their bodies, one function of which is to help control the permeability of membranes. Sorry if that sounds jargony, but it's the fastest way to summarize! The detergent isn't actually just an "irritant", its molecular properties alter the skin barrier. (This isn't about their size or shape, it's about their hydrophilic properties.) Soaps as defined on my site have hydrophilic properties closer to skin lipids that are stripped in washing, so remaining residues (as there inevitably are after washing) don't change the permeability the way even small traces of detergents do.

The web site never tries to claim that solving eczema is just one thing, but lays out a problem-solving process to help people get to the root of things regardless. I'm sorry it didn't help you solve yours, though! There is a mom who used the site to solve her son's terrible eczema this past summer, who put up her own site to write about their journey and help others. It's very inspiring and helpful (the link is to a summary of their history), with many tidbits for related problems, particularly for those who used steroids for a long time before implementing the site: hhttp://www.sammysskin.blogspot.com/2012/06/progression-of-sams-eczema-over-time.html

I have no affiliation with her site, it's just beautifully written and might be helpful. I wish you luck finding a solution.

Charlotte said...

My own personal anecdote is that I'm allergic to sulfates. That's only according to me and my dermatologist. Yes, I get the "itch". If you think scratching your scalp until it bleeds is no big deal, you are mistaken.

Susan Barclay-Nichols said...

Hi Charlotte. I'm sorry you suffer this way, but your experience is definitely rare (and in fact, I've not heard of it before). I don't think it's not a big deal, but you recognize this is an experience unique to you. I hope you've found other surfactants you can use that don't cause this kind of misery!

Tracy said...

Our hair is attached to our scalp, and shampoo comes in contact with the body when we rinse (albeit, more diluted). SLS is a known irritant.

"We found a pronounced reaction to SLS, and a far milder one to SLES. Even at the highest concentration the skin reaction to APG was hard to detect. During the regeneration period (day 3-10) SLS showed even at day 10 an increased TEWL at all concentrations tested." http://www.ncbi.nlm.nih.gov/pubmed/12641575

I haven't found the original source, but I believe SLS is used to create irritation for some studies, because it is an effective, reliable irritant.

Individual reactions aren't mere anecdote. There is a large, and, seemingly, increasing, population that's sensitive to many chemical ingredients*. "For the first time, this study, based on a large data pool, revealed a significant association between reactivity to the irritant SLS and erythematous reactions to certain allergens. With SLS as a marker for hyperreactive skin at hand, some of these reactions can now be classified as irritant more confidently, particularly if there is no history of exposure to the allergen." http://www.ncbi.nlm.nih.gov/pubmed/12694214

* There is less data on sensitivity to natural substances, but lavender essential oil is considered an irritant in Japan, probably because of a longer history of widespread exposure there to high-concentration lavender (through lavender plants).

People who are sensitive are exposed to sulfates in a number of products, many times products containing numerous other potential sensitizers.

A very small study found that removing sulfate exposure allowed skin to rebound (no long-term effects from temporary exposure). It's a miniscule sample, but interesting that they chose SLS to induce irritation, and used acetone as one of the controls. "Sodium lauryl sulfate (SLS) induced irritant contact dermatitis at 3 concentrations (0.025% to 0.075%). ...Upon repeat exposure, an immediate and augmented response in erythema, TEWL, skin colour reflectance and LDF developed." http://www.ncbi.nlm.nih.gov/pubmed/16283906

Sulfates may not be bad for hair per se (SLS in cheap, poorly-formulated products would naturally produce inferior results to higher-quality products), but it is bad for skin.

Skin irritation is cause for concern. Inflammatory reactions ARE implicated in some cancer research and aging studies. That doesn't mean SLS causes cancer, but it does suggest that avoiding products that irritate the individual is a prudent approach. And sensitive individuals will tend to have cross-sensitivities, so applying additional products to counter irritation can create even more irritation. My avoidance of sulfates is because of skin effects; over-drying of hair seems more related to formulation quality than sulfates themselves.

Susan Barclay-Nichols said...

Not all sulphates are the same. SLS is a known irritant, but what about the dozens of other sulphates? And what about the methosulphates? I appreciate the links you posted very much, but we have to take into consideration that the SLS was left in the skin for a much longer period of time then we would use in our hair or skin. Almost everything is an irritant at a sufficient level, including natural oils. (See the post I wrote on whether oils are absorbed by our skin to see the effects of oleic acid.) Thanks for taking a scientific approach to your comment, Tracy.

I don't say that anecdotes aren't valid - they can be, depending upon the context, and our personal preferences are the reason to get into making our own products - but we need to recognize the difference in having an opinion and science. It isn't valid to say that I think SLS causes cancer, but it is valid to say that I don't use SLS because I don't like it or that I think it causes irritation to my scalp and so on.

I don't use SLS because I know there are more lovely surfactants available at my local suppliers and because I know it can irritate, but I'll happily use SLeS, ALeS, sodium coco- sulphate, sodium myreth sulphate, and others because they aren't irritants when used in safe usage levels in rinse off products. But that's my choice!

Susan Barclay-Nichols said...

Another thought, Tracy. Those studies didn't combine surfactants or use mildness enhances the way we do when making products, which can have a huge effect on the irritation level of our surfactants.

As an aside, cold process, alkaline soap is incredibly irritating for our skin....

Thanks for starting an interesting discussion!

Tracy said...

Susan, I respect your choice to use sulfates - I don't think I'd read your blog if I thought it is automatically "bad" to use chemicals. I just also respect the choice to avoid them.

Many sensitivities are like allergies - they're not "supposed to" be there, but they are, and they aren't always easy to diagnose. For some people, formulating milder recipes is enough; for others, complete avoidance of sulfates, even mild ones, is the only way to find relief. For other people, mild formulations will work, but it's an awful lot of work figuring out which formulation works or doesn't.

I had considered inflammation a cosmetic issue until my skin cancer surgeon suggested otherwise. I did not mean to suggest that sulfates cause cancer; just that inflammatory processes break down the body's defenses against cancer and sometimes activate processes, like release of oxidants, that create favorable conditions for cancer to develop.

It's interesting you bring up cold process soap.

http://www.healthmegamall.com/Articles/BabeskinArticle189.pdf
This is an interesting study showing little measurable difference between syndets and "classical" soaps at pH 9.6 (much higher than most cold process soapers formulate for), although I didn't see any description of the formulations used for either version.

Cold process soaps combine surfactants - sodium salts, but each with different properties - and often use mildness enhancers, too. It's probably no more valid to conduct research on "soap" without specifying formulation than it is for syndets, but you feel comfortable making blanket statements about cold process soap while research on syndets is inconclusive if it ignores formulation.

You sometimes try to create natural recipes or organic recipes, and, for all the effort you put in, it seems like you get crickets chirping in response. I respect the effort you make and wish I had time to read daily or even weekly. You asked about sulfates and I shared a perspective. Science is constantly emerging and we all have to make informed guesses based on existing research, valid questions that haven't been fully tested, and inferences from other research. Your informed guesses make you happy with sulfates. Others choose to avoid them. In 20 years, maybe science will have a definitive answer of who can tolerate which sulfates.

Christina said...

I avoid it because of my hair type. It's coarse and prone to dryness, so I prefer gentle surfactants and incorporate stearamidopropyl dimethylamine in other products to remove build-up.

I also prefer surfactants I can use for multiple products, and since I'd rather use SCI on my face than SLS, I favor SCI. And lactylates. I'm a big fan of lactylates.

I guess I just think there are nicer surfactants out there. I just wish they were as cheap as SLS.

Lisette Warren said...

Hi Susan,
as I understand it, SLS is fine for use in shampoos for most people, hence why you see it all over brands in the supermarket. However, there has been an increase in the amount of people with links to increased sensitivity and irritation. I believe this caused for the introduction to sulphate free shampoos, but as I said for most of the population SLS causes no problems. SLeS even less so. I will try to find some scholary type articles as I want to back up what I am saying! In terms of what goes into the "sulphate free" category, I think taurates and sarcosinates fit here.

I think the reason SLS can be an irritant is because even though it is used in low usages, it is found in lots of daily products, so we become more exposed to it. I should note that I do agree with you and don't avoid SLS in products, but for those with dermatitis and such, it can cause some problems.

Lisette Warren said...

Just as an extra point of interest, MIT, a widely used preservative is having restrictions put on it for the same reason I stated earlier. Because it is used at low thresholds in everything, there was too much exposure to the public and an increase in sensitivity was found. I'm not saying I agree with this, but I could see SLS heading the same way.