Written by Evelyn Ngugi on May 13, 2010
It’s all about the pH
Many naturals have promoted baking soda, or sodium bicarbonate, as an ingredient that cleanses the hair as a shampoo and softens the hair as a conditioner. Some have even promoted it as something to loosen the curl pattern.
Baking soda is in fact, a chemical, so to understand its effects on our hair, we need to understand its pH. If you think back to good ol’ high school chemistry, pH ranges from 0–14, acid to base (alkaline). If something is an acid, it has more hydrogen ions. If something is alkaline, it has more hydroxide ions. A neutral pH is 7.0—the pH of distilled water.
A common example of an acid is lemon juice, with a pH of 2 or 3. Sodium hydroxide, the chemical used in lye relaxers for hair, is extremely alkaline with a pH of 14 (yikes!)
Our hair, when wet, has a pH of about 4.5-5.5. As you can see, human hair is slightly acidic when in its natural state. When applying products to our hair, the key is BALANCE. For our hair to stay natural and healthy, the pH must remain the same. Even the water we use in the shower will raise the pH of our hair! This is why hair products are usually pH balanced. The company takes pH into consideration when creating the product.
Baking soda, the product I was putting in my hair, has a whopping pH of 9.0! It was raising the pH of my hair! The fact that something is acidic or alkaline is more than just a label. It actually affects our strands in a certain way.
Picture each strand of hair as a tube of layers. The outermost layer is called the cuticle. An acid will close the cuticle layers, while a base will open them. Neither action is bad on its own. But once again, balance is key.
When the cuticle is raised, moisture is allowed into the hair, but it is also let out. If something isn’t done to close the cuticle back up, any moisture that was applied is lost. Things like temperature even affect the hair cuticle. For example, hot water opens the cuticle, while cold water shocks it shut. That is why most naturals shampoo their hair with warm water, but rinse the conditioner out with cold.
So, alkalines open the cuticle, while acids close it. Baking soda mixtures like the rinse and conditioner will cause our hair to absorb too much water (yes there is such a thing as too much moisture!). Without anything to lower the pH of our hair back to normal 4.5- 5.5 and close those layers, the moisture will not be retained. As a result, those layers will stay raised and jagged, making the hair feel rough and unmanageable.