Sunday, December 26, 2010
Iron Chemist: Sodium lactate
Here are the rules. Every week I will ask my husband to choose a number between 1 and 9. These represent boxes of supplies in my workshop. Once he has chosen a number, he will choose an item randomly from the box and I must make 2 - possibly 3 - products that include that ingredient. I will post the ingredient on Sunday and the products I've made out of said ingredient on Saturday along with the recipes. (If you wish to play along, you aren't limited to the same time frame and you don't need to make 2 or 3 products.) The only exception will be preservatives - I use them in everything anyway, and it won't end up being a very interesting product!
Unlike Iron Chef, you don't have to make the featured ingredient the main ingredient because we don't want to use our ingredients at unsafe levels.
As a note, I will change the order of the boxes every week, choosing another number 1 and counting from there because there's a chance he won't choose boxes number 1 or 9 because they're at the beginning and end.
I do love sodium lactate! It's inexpensive, easy to use, and doesn't leave any sticky residue in your products. It's a metal-organic humectant (the Na - sodium - is the metal part), as opposed to a poly-alcohol, like glycerin. It is found in our skin's natural moisturizing factor, and it's a very effective humectant. How effective? Very effective.
It has been found to improve the barrier properties of our skin (in studies, there is a decrease in the trans epidermal water loss, which is a good thing), it is believed to stimulate ceramide synthesis in the skin, and it increases the plasticity of our skin. It also acts as a mild AHA, which can help reduce "the look of fine lines and wrinkles".
It has a really high water holding capacity (meaning it's a very effective humectant), and it is about 1.5 times more effective in this department than glycerin.
So why not use it in everything? It can help treat acne and "signs of aging", and it's a very effective humectant. On the down side, it can make your skin sun sensitive, it can increase the rate of cell exfoliation (which is both good and bad), and it loses its efficacy when you've washed the area in question. So for something like a hand lotion, you're going to lose your humectant after the first hand washing! So great for body butters, foot lotions, moisturizers, toners, and other leave on products - not so great for products like body washes, hand lotions, or surfactant systems where you are going to be washing it away.
I use sodium lactate at 2.5% or lower in my products because at 3% it can make you sun sensitive, so I'd recommend it at 0.5% to 2.5%. If you're using it in a product where the sun doesn't matter - for instance, for a night time foot cream - you can go as high as 5%.
This one's going to be hard as I use it in just about everything already!