Wednesday, April 23, 2008

What's in that soap?

My daughter was watching NBC Dateline on toxic chemicals in common ingredients and asked me to print off the list--never could find the list, but I decided to look at my own common, people products. She was particularly concerned about "moisturizers," products that keep your skin and hair soft, and I'm guessing she uses more of these products than I do (even though she's always been much prettier, even without help). Usually these are scare stories and I'm betting a lab rat would die if you washed him too many brownies and milk, too. So I'm just picking a few things one thing up at random:
    Meijer moisturizing liquid soap, Milk & Honey. The label says, "contains light moisturizers to help leave your hands soft . . . great for the entire family. Warnings: For external use only; avoid eyes; keep out of reach of children [scratch that "family" part, I guess]
      sodium laureth sulfate
      sodium chloride
      sodium lauryl sulfate
      cocamidopropyl betaine
      glycol stearate
      cocamide mea
      DMDM Hydantoin
      tetrasodium EDTA
      citric acid
      Aloe Barbadensis gel
      MEL (honey) lactose
      milk protein
      silk peptide
      hydrolized silk protein
      D&C yellow no. 10
      FD&C red no. 40
You don't need to go to a health web site, you can go directly to a toxic substance list by the government, but one that's broken down by cosmetic ingredients is useful. So here's the first chemical ingredient, sodium laureth sulfate
    Used in car washes, garage floor cleaners and engine degreasers - and in 90% of products that foam. [That sounds a bit harsh for a foaming ingredient that is widely used in cosmetics also. Do you suppose they've left something out or misled you?]

    Animals exposed to SLS and ALS experience eye damage, central nervous system depression, laboured breathing, diarrhoea, severe skin irritation, and even death. ["Exposed." Does that mean full strenth into the eyes, not mixed in tiny amounts with other ingredients, then mixed with water when it's on your skin for a few seconds?]

    Young eyes may not develop properly if exposed to SLS and ALS because proteins are dissolved. SLS and ALS may also damage the skin's immune system by causing layers to separate and inflame. It is frequently disguised in semi-natural cosmetics with the explanation "comes from coconut".[So, does it come from coconut or not? What's with the scare quotation marks. How young is young, and whose eyes? How much is on the skin to cause it to separate and inflame?]
Hmm. Doesn't sound too good--or it's an anti-industry site. Let's look for another site.

Keeping in mind that hardly any group--retired bloggers, housewives, mothers or health care staff--is washing their hands often enough or even getting close to guidelines.. Alcohol rub is probably the best for disinfecting--you need about 2-3 minutes of sudsing and scrubbing with a non-medicated soap to remove even some of the microflora on your hands, and if you didn't have these various agents in your soap, you'd probably have very raw knuckles very quickly, and develop an infection from that. (BTW, doctors are less careful than nurses, did you know that?)

So then I checked for this ingredient, but it is only looking at a circulating e-mail on SLS and cancer, not the NBC story. He says it is a foaming agent in shampoos, soaps, toothpastes and cleaning agents, provides links to various sites, FDA, OSHA, NTP and IARC, and says they all say it is non-carcinogenic. I try those sites and either find articles so technical that I can't read them, or I find "no results."

Here's what I found on sodium laureth sulfate at an Australian government site about dermal irritation--nothing close to these quantities appears in soap, shampoo or moisturizer products, and multiple applications were needed to induce an irritation. Huge quantities taken orally did kill lab rats, but generally we don't drink our shampoo and liquid soap.
    "Sodium laureth sulfate: A large number of studies were performed with a variety of concentrations under occlusive patch for 24 – 48 hours. Applications produced no irritation at 5 – 5.6%, mild erythema and oedema at 6 – 10%, 17.5% and 26%. Severe irritation occurred at 15, 25, 28 and 30%. Severe irritation was produced in 3 applications of a 15% solution on consecutive days but similar studies with 17.5% produced only mild irritation. Single applications of 26 and 28% produced mild and moderate irritation, respectively, and an application of 58% produced no irritation. Three studies using 30% applications for 3 days produced severe irritation. Effects on the skin and hair cycles were investigated by application of the chemical daily for 65 days. A 60% concentration caused inflammatory changes, epidermal hyperplasia, epidermoid cyst formation and diffuse hair loss. A 30% concentration caused similar but less severe changes and 9% caused no changes.
Keep in mind that the reason cancer is at the top of the death list today is that we are an aging population, and if you live long enough, you'll get it. But also, through various medical advancements and miracles, the reasons people died young 100 years ago, have been eliminated. The big killer of babies and children in 3rd world countries is diarrhea--bad water. Another killer of children in those countries is malaria (with the help of environmentalists who got DDT removed). We don't have those diseases in the U.S. We are killing ourselves young with behavior related health problems--lack of exercise, too many calories, sexual promiscuity, and nicotine.

I think we probably have a lot of SLS and SLES on our skin because it's in so many products, but we're not going get rashes, die or develop cancer--unless maybe it's part of our diet, or we smoke it, or use it during sex, or stay inside and wash our hair rather than going outside to walk.

Final Report on the Safety Assessment of Sodium Laureth Sulfate and Ammonium Laureth Sulfate. J Am Coll Toxicol. 2: 1 – 34 (1983).
Final Report on the Safety Assessment of Sodium Lauryl Sulfate and Ammonium Lauryl Sulfate. J Am Coll Toxicol. 2: 127 – 181 (1983).


Hazel said...

I do not use liquid soaps period!
I use REAL soap and when I can afford it it's one that has olive oil as a base.
Detergent for washing clothes and dishes yeah but rubber gloves a must!
Moisturiser and hand cream from an apiary in Wales.
I'm not a fanatic about it but I've been so much more healthy since avoiding the harsh chemicals that I think it's worth it and it doesn't actually cost a lot more.

mdoneil said...

SLS is a anionic surfactant. It contains cabon, hydrogen, sulphur, oxygen and sodium (so do you and I)

[c12 H25 SO4 Na]

The product you describe has sodium laureth sulfate (SLES) as the first ingredient(as opposed to laurel) that is different from SLS, but it too is an anionic surfactant. (and indeed simply exothylized SLS - to make it more foamy)

These are detergents that lower the surface tension of water to allow for better cleaning. (there are a lot of hoops to jump through to explain the process.)

It is also used in sandy soils where the water does not penetrate to improve plant root water exposure. I have sprayed it on my lawn in Florida - they are marketed as soil wetting agents. They work wonders. If you have sandy soil try misting it with dishwashing liquid and then watering, the difference will be astounding.

I knew that Chemistry degree would come in handy.

Norma said...

Thank you Matthew. Librarians are so cool!