Micellar water: critical micellization concentration (CMC) of different surfactants

As I hinted in this post, there is a property that surfactants have called critical micellization concentration (CMC). I did a bit of research on it when I was trying to find out how much surfactant is used in a micellar cleansing water (which is obviously a different amount for different surfactants)... it can't be "micellar" water unless there are micelles! If you don't know what a micelle is, go spend a few minutes at the University of Google, and meet me back here.

So, to simplify, the CMC is the lowest concentration of a surfactant that will form micelles in water (or whatever diluent the researcher is determining/stating the CMC for... we are really only concerned about water), so it is the lowest concentration of surfactant you need to be able to call your solution a micellar water!

These values didn't end up being super helpful in determining proper surfactant concentrations for micellar cleanser, since they are so low as to likely be inadequate for cleansing purposes, but they are interesting nonetheless and, by definition, form the lower limit for surfactant concentrations in a micellar cleanser.

The ones I have collected are for surfactants I own; if you know others you'd like to submit to this list, please comment with the values! CMCs are listed in various units including ppm (parts per million), mol/L (moles per litre), and g/L (grams per litre). I am listing in grams per litre of water, since that is most useful in cosmetic chemistry formulating, but if you are a nerd like me you can sort out how to convert from mol/L to g/L (that's how I got the value for decyl glucoside).

CMCs of various surfactants
1.7 g/L caprylyl/capryl glucoside
0.7 g/L decyl glucoside
0.06 g/L (60 mg/L) polysorbate-20
1.1 g/L PEG-40 hydrogenated castor oil

N.B. It is just my assumption, but I would think that the CMCs refer to concentrations of active chemicals in your surfactants, since they can come in different strengths. That is, you'd need 10 grams of a 10% active surfactant to get 1 gram of the actual surfactant ingredient into your formulation. The stuff as it comes out of the bottle is not 100% active; for example, the decyl glucoside I have is 51% active. Note that I write my formulas for "as it comes out of the bottle." So my decyl glucoside micellar water that was "1% decyl glucoside" actually only had 0.51% active decyl glucoside in it.