NIC Esthetician Written ExamScientific ConceptsEasy
A cosmetic chemist is formulating a new cleanser and aims for a pH that is slightly acidic to maintain the skin's natural acid mantle. Which of the following pH values would be most appropriate for this formulation?
- A8.5
- B5.5
- C3.5
- D7.0
Show answer & explanationAnswer & explanation
Correct answer: B. 5.5
The skin's natural acid mantle has a pH typically between 4.5 and 5.5. A cleanser with a pH of 5.5 would be slightly acidic and help maintain this protective barrier.
Why the other options are wrong
- A. A pH of 8.5 is alkaline and would disrupt the acid mantle.
- C. A pH of 3.5 is too acidic for a general cleanser and could cause irritation.
- D. A pH of 7.0 is neutral and less ideal for maintaining the slightly acidic acid mantle.
Skin's Acid Mantle pH
The slightly acidic film on the surface of the skin, composed of sebum and sweat, which acts as a protective barrier against bacteria and environmental factors.
- Healthy skin pH is typically 4.5-5.5.
- Helps inhibit bacterial growth.
- Disruption can lead to dryness, irritation, and increased susceptibility to infection.
Memory trick: Keep skin slightly sour, not soap-salty.