What does the irritating potential of fruit acids depend on?

• The lower the pH level the more intense will be the intended irritation of the skin which subsequently leads to an increased recovering effect. 
• With a low pH level and low concentration the irritating effect will also be lower than with a low pH and a high concentration as the skin is able to neutralize part of the acid which means that the pH level will increase during the treatment.
• A buffered fruit acid in high concentration will stabilize the pH level. The risk of an uncontrolled burning of the skin instead of the intended controlled irritation is considerably lower due to a higher pH level as the timeslot for the treatment will be longer.
• The keratolytic effect of fruit acid salts as well as of urea depends on the concentration or in other words, the effect augments with the concentration.

Dr. Hans Lautenschläger