What similarity in pH do all cleaning products have in common (soap, shampoo, cleaner)? Why is this important?

For a science project..


What similarity in pH do all cleaning products have in common (soap, shampoo, cleaner)? Why is this important?
The pH of cleaning products, such as soaps, shampoos, and cleansers, ranges from about 4.5 to 6.0, which is mildly acidic:





Soap pH = 5.0-6.0


Shampoo pH = 4.5-5.5





Such a pH is important, because it is very similar to the natural pH of skin and hair:





Skin pH = 4.0-6.0


Hair pH = 3.5-5.5





If there was a substantial discrepancy between the pH of cleaning fluids and skin or hair, then these external tissues could be damaged by exposure to cleaners. Because the pHs are similar, cleaners are safe to use on skin and hair.