HOW DOES BLEACH WORK AND WHAT DOES IT DO TO HAIR?
Each strand of hair is made of protective cuticles and a cortex at the centre – which is where your natural colour pigment lives.
When you apply bleach, the hair strand swells and expands, lifting the cuticles so the bleach can enter and pull the pigment out.
This leaves the hair porous and ready to absorb your toner and semi-permanent hair dye.
HOW LONG CAN I LEAVE BLEACH ON MY HAIR FOR?
You can’t leave bleach on forever, waiting for it to get the colour you want. This will stress your hair out.
The width and shape of your individual hair strands define how long you can leave the bleach on for. Hair that is coily or fine (whether it's straight, wavy or curly) will lift a lot faster than thicker, coarse hair strands.
However long the instructions that come with your bleach kit say that you can leave the bleach on for your hair type is the lightest you can go in one session at home.