Alkaline hair isn't a hair type like straight or curly hair. Instead, it refers to hair that has been treated with an alkaline substance, raising its pH level. This is most commonly seen in hair coloring and perming processes.
How Alkaline Substances Affect Hair
The natural pH of hair is acidic, around 3.67. Alkaline substances, with a pH above 7, have the effect of raising the hair's pH. This is crucial in several hair treatments:
- Hair Coloring: An alkaline hair color elevates the pH, causing the hair cuticle (the outermost layer) to swell and open. This allows the color molecules to penetrate deeper into the hair shaft, resulting in more significant color changes, including lightening and intense color saturation. [Source: Wella Professionals Blog, Feb 21, 2022]
- Perming: Alkaline perms use chemicals to alter the hair's structure, creating curls. The alkaline solution softens and swells the hair cuticle, making it more receptive to the perming solution. [Source: Quora, April 5, 2023]
It's important to note that while alkaline treatments can achieve dramatic results, they can also be damaging if not done correctly by a professional. The swelling and opening of the cuticle can weaken the hair, leading to dryness and breakage if not properly balanced with acidic treatments afterward. The scalp's pH is slightly higher (around 5.5), and maintaining a balanced pH is key to healthy hair and scalp. [Source: Head and Shoulders]
Alkaline vs. Acidic Hair Treatments
Many hair products and treatments, including shampoos and conditioners, aim to maintain or restore the hair's natural acidic pH. Acidic treatments help to close the cuticle, reducing damage and improving shine. The use of alkaline and acidic products is often balanced to minimize harm and maximize the effect of the treatment. [Source: Combe Education, April 3, 2022, and The Ledger, September 9, 2002].
The term "alkaline hair" doesn't describe the inherent nature of the hair itself but rather the effect of alkaline chemical treatments on it.
