Saturday, May 19, 2012

Facts I Know, and Some that Aren't Facts

Many years ago, I heard Ralph Nader say that he might be the only person in the U.S. who doesn't use any cosmetics. Which seemed odd at first, but then I got his main point: Toothpaste and shampoo are classified as cosmetics, and there aren't too many of us who don't use those.

Nader uses soap instead of shampoo and baking soda to brush his teeth.

Ralph Nader photo collaged to add him sticking out his tongue with a bottle of shampoo and a tube of toothpaste floating near his head
(The toothpaste I use, Sensodyne, should probably be treated as an over-the-counter drug, since it has an active ingredient. Well, then again, I guess all fluoride toothpaste does, but Sensodyne includes instructions about contacting a doctor, so that seems a bit more extreme.)

I'm filing this under Facts I Never Knew, even though I already know it. But perhaps you didn't know that shampoo and toothpaste are considered cosmetics, and when I first heard it I was surprised -- so I think that counts as a fact I never knew until a certain point.

I was thinking I might include another "fact" I heard close 30 years ago: that baby shampoo doesn't cause tears because there's an anesthetic in it. I believed this when I first heard it at the tender age of 25 or so, but wiser, cynical, Google-enabled me thought better of just regurgitating that one. And I found, of course, that it's not true.

I love this explanation of "no more tears" shampoos from a Snopes forum:

The active part of shampoo comes from a family of chemicals known as "surfactants." Sodium Laureth Sulfate and Potasium Laureth Sulfate are two of the most common. These handy little molecules have one end which is hydrophilic and another which is hydrophobic. The result is that one end grabs oil from the hair and then hitches on to the water for a short ride into the drain. The problem with suractants is that, when they get into the eyes, the keep doing their job. The tear film on the eye is mostly water with a bit of oil and it acts as a protective barrier. Surfactants pretty much remove this protection. It gets worse though, they do a fine job of stimulating nerves in the eye. This hurts.

No Tears shampoos also contain surfactants, but they piggyback a larger molecule on the surfactant to keep it from getting into the sensitive tissues in the eye. The substance is called and Amphoteric Surfactant. The molecule still holds the same oil/water binding properties, but it is too big to get through tissue etc. The result is... well... no more tears.

Two problems with amphoteric surfactants. 1) They are rather expensive to produce. 2) They don't lather.

Consumers like lathering because it makes them think the shampoo is working. I invite any of you to buy a few different varieties of "no tears" shampoo, use them, and try to work up a decent lather. You'll end up with very clean hair, but only a few suds.

Amphoteric surfactants are how the shampoos keep tears away.

[signed by] Jon 'No lather, no tears, no novocaine" Up North 

1 comment:

Michael Leddy said...

I just learned something. Several somethings. Thank you.

I think that the only soap that works well as a shampoo is Dr. Bronner’s. The oils make the difference.