Comparison of Damage to Human Hair Fibers Caused by Monoethanolamine- and Ammonia-Based Hair Colorants

The study conducted by Aaron D Bailey et al., published in 2014, compared the damage to human hair fibers caused by monoethanolamine (MEA)- and ammonia-based hair colorants. The research found that MEA-based formulations can cause more damage to hair than ammonia-based ones. In the most extreme case, MEA-based formulations caused up to 85% more damage than ammonia. The damage was assessed through various methods including Fourier transform infrared spectroscopy (FTIR) for cysteic acid level measurement, scanning electron microscopy (SEM) for visualizing cuticle damage, and protein loss measurement. The study suggested that if the odor of ammonia is a concern, it would be better to minimize the volatility of ammonia rather than replacing it with potentially more damaging alkalizers like MEA.