From: Denise Kingsley (straighttalkers.lamasbeauty.com)
I got this info from Beth Minardi...
INOA means: Innovative, No Ammonia. INOA contains MEA. Now, as new products like INOA find their way to our salon shelves, so does plenty of new information and misinformation. New non-ammonia hair coloring products offer one option for both delivering new hair color AND covering gray. But before you jump from one product to another, it's a good idea to be completely certain about ingredient claims. Here is some important hair color information you might find helpful when clients ask you about everything new in coloring:
MEA is Monoethanolamine. It is an alkaline reactive chemical compound that is produced by the reaction of ethylene oxide with ammonia. It exists in liquid form and produces almost no odor.
What is ammonia? Ammonia is an alkaline compound of hydrogen and oxygen that is both naturally occurring and human made. It is water soluble, highly reactive, exists in both gas and liquid form, and has a strong odor.
How does MEA perform in hair color? MEA opens the hair's cuticle. However, it is not as efficient as ammonia at penetrating into the cortex of the hair. Therefore, it does not allow the color ingredients to penetrate the hair strands as well as ammonia.
How does ammonia perform in hair color?
In hair color, ammonia is very efficient at opening cuticle, which allows color to penetrate more efficiently into the hair's cortex. When permanent color and peroxide meet ammonia, ammonia acts as a catalyst. This reaction is what removes natural pigment from the cortex and allows artificial color to deposit inside the cortex.
MEA's reaction with peroxide is weaker than that of ammonia. The molecule of MEA is 3.5 times larger than the molecule of ammonia. Thus, it may not be as effective as ammonia/peroxide at lifting natural color out of the hair or depositing color into the cortex.
MEA and ammonia are not fundamentally bad for the hair. It is the AMOUNT of MEA used in a color that can create potentially negative results. Typically 6% to 10% MEA is used in color. For ammonia, the amount ranges from 1.5% in darker shades to 3.5% in high lift shades.
Most hair color companies prefer ammonia because, historically, the color results of ammonia based permanent hair color remain more predictable than MEA based color, providing longevity, vibrancy and superior gray coverage.