Study involving Sodium Lauryl Sulphate

[ChloeDharma]

In a search i found this article http://www.mcponline.org/cgi/content/abstract/5/3/523
I generally avoid sulphates in products but this has reminded me why. The part i found particularly worrying was this bit
"Short term pretreatment with SLS disorganized the stratum corneum, extracted partial lamellar lipids, induced the maturation of Langerhans cells, and did not result in epidermis thickening."

[pepperminttea]

It's almost certainly me being quite thick, but I don't suppose you could give a gist in laymen's terms? :o

[Tinose]

If I'm reading it correctly, the SLS basically irritates the skin and makes it easier for the vaccines to penetrate?

[spidermom]

And how many of us leave a swath of pure SLS on our scalps (or any other part of our skin) for at least 10 minutes?

[may1em]

And how many of us leave a swath of pure SLS on our scalps (or any other part of our skin) for at least 10 minutes?

I like to do that before AND after I sit in a tub full of parabens for the rest of the morning. Then, I like to smear on a thick layer of -cones.


I'm in a funny mood today.

[teela1978]

And how many of us leave a swath of pure SLS on our scalps (or any other part of our skin) for at least 10 minutes?

This.

To be fair, they looked at 0.1, 1, and 5% dilutions, and to my knowledge 1% is typical for shampoos. But when used as a shampoo it is further diluted down, and rinsed out (unless I do things oddly) within 60 seconds.

That is a cool study though, thanks for sharing it. Honestly, I think this is why I like SLS, it cleans away dead scalp skin and excess lipids (sebum) without too much mechanical cleansing. CO and other non-chemical methods require a lot of scalp scrubbing to cleanse my hair, and generally result in a lot of shedding, and a not-so clean scalp.

[Aries_jb]

My feelings with many studies that conclude that chemicals are bad is that they usually do not test it in a real life scenario. Informative, yet you have to take it with a grain of salt.

That said, I try to avoid SLS because if I use it too often my scalp feels tender.

[ericthegreat]

This is yet further confirmation for me that I'm doing the exact right thing by limiting my use of shampoo to only once every two or once every 3 weeks. I CO on a regular basis, and only use shampoo to either remove an oiling I just did the night before or I shampoo to clarify my hair to get rid of any buildup I get from my Suave Coconut conditioner.

[ChloeDharma]

My feelings with many studies that conclude that chemicals are bad is that they usually do not test it in a real life scenario. Informative, yet you have to take it with a grain of salt.

That said, I try to avoid SLS because if I use it too often my scalp feels tender.

Ah, from the way i read it the study wasn't actually criticising SLS but demonstrating it's effectiveness for transdermal delivery of a vaccine.

Spidermom, i thought someone might point that out, but my thoughts on it are that it still demonstrates the ability of SLS to disrupt the skins function to some extent and reduce it's ability to act as a barrier.
Don't forget, many people happily soak in a bath full of bubbles produced by the SLS in a bubble bath for longer than 10 minutes so it's not just about shampoo use.

I'm not actually saying people should or shouldn't use products with it in, i'm just passing on some information i stumbled upon to help others decide for themselves.

[Pierre]

It's almost certainly me being quite thick, but I don't suppose you could give a gist in laymen's terms? :o
The stratum corneum is the blype layer of the skin. Disorganizing it means it lets things in that it shouldn't.

A lipid is a fat, wax, or similar biochemical. What a "partial lamellar lipid" is, I don't know.

The Langerhans cells are cells in the pancreas that regulate blood sugar.

[teela1978]

The Langerhans cells are cells in the pancreas that regulate blood sugar.

Langerhans cells to my knowledge are skin-residing immune cells. Essentially, the SLS "activates" them, which would make them more sensitive to things that normally would cause them to initiate an inflammatory cascade (bits of bacteria and such)... but doesn't seem to cause inflammation on its own.

ETA: wikipedia link (http://en.wikipedia.org/wiki/Langerhans_cell). Islets of langerhans are what you were thinking of.

ETA: Actually this makes total sense now that I think about it. Langerhans cells are antigen presenting cells, so if they were being activated, they would be taking up loads of any bits of whatever it was they were vaccinating for, and would later be presenting lots of it to T-cells and initiating immunity.

[alys]

Interesting stuff for sure. Personally I would never use SLS to clean my skin, it's very drying to me. I use castile soap and I find it cleans just as well w/out stripping or drying. I do use SLS shampoo occasionally in my hair however, because it does remove everything without requiring me to scrub like the dickens. One thing I have discovered for my own hair in numerous labratory, (ok bathroom), tests is that poos with SLS dry the crap out of my hair if I use them regularly. That fact alone, nevermind the internal effects of the chemical, is enough for me to choose only to use SLS once per week if that.

[spidermom]

Ah, from the way i read it the study wasn't actually criticising SLS but demonstrating it's effectiveness for transdermal delivery of a vaccine.

Spidermom, i thought someone might point that out, but my thoughts on it are that it still demonstrates the ability of SLS to disrupt the skins function to some extent and reduce it's ability to act as a barrier.
Don't forget, many people happily soak in a bath full of bubbles produced by the SLS in a bubble bath for longer than 10 minutes so it's not just about shampoo use.

I'm not actually saying people should or shouldn't use products with it in, i'm just passing on some information i stumbled upon to help others decide for themselves.

Understood. I happily soak in a bath full of bubbles from an SLS product, but one must consider the extreme amount of dilution one squirt of an SLS product in the number of gallons it takes to fill a tub. I don't objectively know if the health effects are negligible, but I feel they are. I have no ill effects, no dry or irritated skin - nothing.

[kittensoupnrice]

What happens if someone sits in a bubble bath for half an hour and then doesn't adequately rinse off? Does the SLS eventually neutralize on your skin, or does it just sit there?

The article also mentions SLS being absorbed into the skin. How long does it take for SLS to pass out of your skin?

It's probably okay to have a bubble bath once in a while, but I'm just wondering what cumulative effects SLS could have when taking not-rinsing and skin absorption into consideration.

[spidermom]

What happens if someone sits in a bubble bath for half an hour and then doesn't adequately rinse off? Does the SLS eventually neutralize on your skin, or does it just sit there?

The article also mentions SLS being absorbed into the skin. How long does it take for SLS to pass out of your skin?

It's probably okay to have a bubble bath once in a while, but I'm just wondering what cumulative effects SLS could have when taking not-rinsing and skin absorption into consideration.

I think you would towel off any remaining residue of product on your skin.

[zule]

I used to take lots of bubble baths--at least two a week--for years. I'd soak for half an hour, adding hot water as needed. (I also burned incense and surrounded the room with candles for light. No electric lights.)

Nothing ever happened to my skin, and I have sensitive skin. The usual amount of bath water is fifteen gallons. A squirt or two of SLS bubble bath is very dilute. And yes, toweling it off is easy.

I wouldn't worry about it unless your skin is ultra-sensitive. You'll have to do some test runs on yours. What works for one person doesn't for another.

[teela1978]

Additionally, skin is constantly sloughing off and your body (unless you have certain health issues) is very good at getting rid of toxins. Anything put on your skin typically won't stay there very long (there are exceptions... I wouldn't call SLS one though).