Considering the Brazilian Keratin Treatment? As with all methods of straightening natural hair, caution should be taken. Here's a little piece of interesting information from Dr. Ali Syed's blog regarding "keratin", "formaldehyde-free", or "aldehyde" BKT:
The truth is that they are actually using formaldehyde and in concentrations that exceed the legal limit. Two of the brands use 1.0% formaldehyde and the third one uses about 4.0% formaldehyde. The legal limit is 0.2%.
All of these brands pose serious health risks as the fumes generated during blow drying and flat ironing can cause headaches, irritation of the breathing pathways, eyes, and mucous membranes. Prolonged exposure can cause even worse problems.
Just remember to be careful and do your research before considering BKT or a relaxer.