How Bleach Affects Tensile Strength of the Hair

This scientific information from chemist C. R. Robbins, and from my salon experience.

A major side reaction of bleach application and processing on the hair. Remember this: In order to bleach the hair, hair lighteners ( bleach), must penetrate not only through the hair’s cuticle… but must also invade deeply into the cortex so that it can begin dissolving melanin ( color) within the hair fiber. This is how the hair lightens.

While today’s very effective bonders and conditioners added to many of today’s top level lightening products DO PROTECT the hair and can create supportive re-bonding bridges which protect from immediate breakage… , colorists must remember that once hair has been exposed to the required alkalinity level present in hair lighteners, the di-sulfonic bonds in the hair have been broken. Forever. Bonders do effectively mend many of the broken bonds, , but do not repair all of the bonds completely or permanently. Bleached hair will NEVER be completely free of a permanent degradation and additional porosity caused by being bleached. So, careful application, avoiding overlapping onto previously treated hair, and complete attention during processing are all very important. Treat lightened hair as a delicate fiber.. a cashmere sweater rather than a pair of denim jeans. And my advice.. go ‘low and slow’… use high volume developer rarely… or not at all. And please follow manufacturer instructions. NEVER, EVER apply a heat source to the hair when bleach is in contact with the scalp!

For a moment, think of a piece of charcoal on a barbecue grill. As the charcoal heats, it gets lighter in color… and it becomes flaky… pulling apart into ashes… now that is NOT exactly what happens to hair… but the comparison here provides a bit of an illustration. I enjoy seeing your comments! Thank you for joining our exclusive page for salon professionals! B