Chemistry 101: What is pH and why does it matter in skincare

“Chemistry… if you’re not part of the solution, you’re part of the precipitate.”

My 7th grade chemistry teacher was the first to introduce me to the pH scale by using litmus paper. We could establish the pH value of any liquid by dipping the paper into the liquids and then watching to see what color the paper turned. For example, it would show red for vinegar (acid) and blue for milk (alkaline.) Purple represented a neutral pH. It was fun!

So, what exactly is pH?

The term “pH” refers to “potential of hydrogen”. It concerns the activity of hydrogen ions (ions are molecules that carry a positive or negative charge) in a water-based solution. Hydrogen makes up two thirds of water, water being two hydrogen molecules plus an oxygen molecule, H²o.

The pH of a solution is indicated by a numeric scale that runs from 0–14. Anything below 7 (which is pH neutral) is considered acidic, while anything with a pH greater than 7 is considered alkaline, also referred to as basic.

How does pH relate to our bodies?

In our bodies, blood or cytoplasm are the “solutions” in which the required ions are floating. The normal pH of human blood is 7.35–7.45. Anything above or below that could have negative effects on our health.