Which alkaline substance helps color molecules enter the hair in permanent color procedures?

• A. Ammonia
• B. Water
• C. Acetic Acid
• D. Sodium Chloride

Answer: (A)

Alkalinity raises the hair’s pH, causing the cuticle to lift so color molecules can enter the cortex. In permanent color procedures, this cuticle lift lets dye precursors and oxidizers penetrate and react inside the hair to form lasting color. Ammonia is a common strong base used to raise pH quickly and effectively, facilitating that entry of color molecules. Water doesn’t change pH enough to open the cuticle. Acetic acid lowers pH, which tightens the cuticle and hinders penetration. Sodium chloride is just a salt and doesn’t provide the pH lift needed to help color molecules enter the hair.