by Kris Jones

Created on: February 13, 2007   Last Updated: April 17, 2007

Bleach is mixed with hydrogen peroxide which opens the cuticle. this allows the bleach to enter the cortex where oxygen is released from the peroxide and makes them colourless. Eumelanin is the pigment that makes the hair black or brown. as the melanin bleaches the pheomelanin becomes more noticable. this is the pigment that makes the hair red or yellow.
As bleaching proceeds the hair becomes lighter and lighter, changing through a range of shades. As bleach has no target colour (unlike other colours which can be like a dark brown or warm brown for example) the result colour depends on the proportions of eumelanin and pheomelanin in the hair.

As the hair is now on a base (how light or dark) that would be unreachable with any other colour, another colour is then applied to kill off any unwanted tones in the hair (if needed)

There is no real danger with bleaching hair aslong as its done under professional supervision. the damage to hair starts to begin when the hair is bleached and then bleached again, causing breakage and irreversable damage to the cuticle. leaving bleach on too long can also have disasterous results, making the hair into a chewing gum substance (ive seen it happen!) or total disintergration. When applying a regrowth to bleached hair it is vital not to overlap.

Peroxides come in different strenghts

3% (10 vol)
6% (20 vol)
9% (30 vol)
12% (40 vol)
18% (60 vol) this peroxide is rare, and even illegal in some places.

Different strengh peroxdes will have different effects on the hair. obviosuly a weaker one will be better for the hair, but will lift slower where as a stronger one will lift faster but will have more pottential to cause damage.

The process of bleaching is visual. Bleach on the hair for a long period of time can have a terrible effect.

It is important to test the condition of the hair beforehand also. these are simple tests that you can carry out yourself.

Porosity - Take a few strands of dry hair, run your fingers up toward the root. the rougher the texture the more porous the hair is

Elasticity - Take a single strand of wet hair. The hair should stretch up to half its length and return. This would indicate good condition. if the hair breaks or coils then it is in poor condition.

If you do these tests and the results are poor then bleaching may not be the best option. You can use a porosity leveler if the results to a porosity tests are'nt great, and a course of reconstructing treatments if the elasticity isnt great either.

If in doubt, dont.

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