PH scale and colour

Open Ended

Why do you think it is important to understand the structure of hair when using colouring and lightening products?

Multiple Choice

Which layer of the hair contains the natural colour pigment (melanin) and is responsible for chemical changes during colouring?

• Cortex

• Cuticle

• Medulla

• Root

Multiple Choice

Which pH range causes the cuticle scales of hair to close?

• 0-6.9

• 7.1-14

• 4.5-5.5

• 8-10

Multiple Choice

How do permanent/high-lift hair colours affect the cuticle layer and the cortex of the hair?

• They close the cuticle and do not affect the cortex

• They open the cuticle and allow active ingredients to penetrate the cortex

• They only affect the medulla

• They make the hair more acidic

Open Ended

What is the natural pH level of hair and skin, and why is it important for everyday shampoos and conditioners to match this pH?

Multiple Select

Which types of hair colouring products penetrate into the cortex of the hair?

• Temporary colours

• Semi-permanent colours

• Quasi colours

• Permanent/high-lift tints

Open Ended

Why do quasi, permanent, and lightening colouring products require a commitment to colour?

Multiple Choice

Which part of the hair is responsible for the natural colour pigment and where do chemical changes occur during colouring?

• Cortex

• Medulla

• Cuticle

• Root

Open Ended

Reflecting on what you have learned about the pH scale and hair colouring, what questions do you still have or what would you like to explore further about how pH affects hair structure?