I started a new project in the lab last week that inspired this blog post. While developing new products, a lot of "tests" are done to make sure all is as it should be. One test that is a constant for all (most) products is pH. pH indicates the level of acidity (or basicity pOH) of a substance. pH is important in cosmetic product development because skin and hair have pH too. The products you apply to your skin and hair should work with your body chemistry, not against it.
The pH scale starts at 0 and caps off at 14 with 0 being highly acidic, 14 being highly basic and 7 being neutral (7 is the pH of distilled water). Either end of the scale results in severe chemical burns. The pH of normal, healthy hair ranges from 4.5 to 5.5 (mildly acidic). Similarly, the pH of basic hair care products range between 4 and 6. Color treated and/or damaged hair tends to have a more basic (alkaline) pH. In a basic environment, the cuticle layer of the hair stands out and appears frayed or split. In order to treat damaged hair, a hair product must be more acidic to smooth the cuticle layer resulting in less tangles and higher shine. The process of treating alkaline hair with acidic products is what is meant by "pH balanced". Knowing that damaged hair has a higher pH indicates that a normal pH hair care product may not be very effective in treating damaged hair.
Putting it all together
I'm sure you've noticed that hair care products are marketed for certain hair types ie dry/damaged/split ends, normal, oily, etc. While these products will often use different ingredients to garner results, one key factor is pH. A formulator will know if the product has a chance of working just by taking the pH of the final formula. I have rarely seen the pH of a hair care product disclosed on the packaging. So as the consumer, you need to get a little crafty. Before trying a product, I suggest you pick up your own supply of pH (litmus) paper and do a quick test. The ideal pH would be 4 or 4.5 to work well on all hair types. No matter how damaged your hair may appear, you never want a product with a pH lower than 3-- and even that's pushing it. **Keep in mind, the pH test only works for products/treatments that contain water.
You're now just a pH test away from gorgeous, healthy hair ;-) Here's to the Glam Life!