INOA (in oh ah) an ammonia-free permanent haircolor system introduced in by L'Oréal Professionnel in June 2009.
Little about the chemistry of hair coloring has changed since 1909 when a French chemist named Eugene Schueller []created the first commercial hair dye. Ammonia Ammonia has been an ingredient de rigueur for women and men who want to lighten their hair, exposing them to its unpleasant odor. Now, scientists at L'Oréal, which was founded by Schueller, have reinvented the chemistry of hair color and replaced ammonia with an odorless substitute.
In place of ammonia, INOA relies on a chemical called monoethanolamine Monoethanolamine, or MEA, which has no odor. MEA is alkaline Alkalinelike ammonia, so it can accomplish the first step in permanent hair dye, which is to open the hair's cuticles. Because MEA does not open the cuticle as efficiently as ammonia, it does not allow the hair coloring ingredients to penetrate the hair strands as well. For this reason, MEA-based hair coloring was only being used to darken the hair and not to lighten hair or color gray.
To boost the haircolor formula, a new component (mineral oil gel) that has a high affinity for hair but not for MEA was added. Right before INOA is put on hair, the oil gel, is mixed together with MEA and the other key components for tinting locks—the oxidative hair dye and the hydrogen peroxide that develops the haircolor. When the mixture is on hair, the oil coats the outside of hair strands and repulses the MEA, driving it to open the cuticle and penetrate the hair. Adding oil changes the ability of MEA to penetrate the hair.
L’Oréal scientists have observed that people who have sensitive scalps are not irritated by INOA. This difference could be attributable to any of the number of modified components in INOA, not just the MEA-for-ammonia swap. INOA does not upset the hair cuticle as much as conventional hair dyes, preserving hair strength.
[www.inoa-us.com Official INOA Homepage]