Esthetician Practice Exam Esthetician Practice Cosmetic Chemistry and Ingredients 1 — Questions and Answers
Question 1: Which pH range is considered optimal for most facial cleansers to maintain the skin's acid mantle?
- pH 4.5–5.5 (Correct answer)
- pH 6.5–7.5
- pH 8.0–9.0
- pH 2.0–3.0
Correct answer: pH 4.5–5.5
The skin's natural acid mantle sits between pH 4.5 and 5.5. Cleansers formulated in this range help preserve the protective barrier and prevent disruption of the microbiome.
Question 2: What is the primary purpose of a chelating agent such as EDTA in a cosmetic formulation?
- To thicken the product texture
- To bind and neutralize metal ions that cause rancidity (Correct answer)
- To increase the product's SPF value
- To act as a primary preservative against bacteria
Correct answer: To bind and neutralize metal ions that cause rancidity
Chelating agents like EDTA bind to trace metal ions (such as calcium and iron) in the formula that can catalyze oxidation and break down preservatives, thereby extending shelf life and stability.
Question 3: Which of the following best describes the function of a surfactant in a facial cleanser?
- It forms a physical barrier over the skin surface
- It provides antioxidant protection against UV damage
- It lowers surface tension to allow oil and water to mix and be rinsed away (Correct answer)
- It increases the viscosity of water-based formulations
Correct answer: It lowers surface tension to allow oil and water to mix and be rinsed away
Surfactants have hydrophilic (water-loving) and lipophilic (oil-loving) ends that allow them to surround and lift sebum and debris, enabling them to be rinsed away with water.
Question 4: Retinol belongs to which broader class of cosmetic ingredients?
- Alpha hydroxy acids (AHAs)
- Retinoids (Vitamin A derivatives) (Correct answer)
- Polyphenols
- Ceramides
Correct answer: Retinoids (Vitamin A derivatives)
Retinol is a form of Vitamin A and is classified as a retinoid. It promotes cell turnover and stimulates collagen synthesis, making it a key anti-aging ingredient.
Question 5: What is the role of niacinamide (Vitamin B3) when used in a skincare formulation?
- It acts as a physical UV filter by reflecting sunlight
- It exfoliates dead skin cells through enzymatic action
- It helps reduce hyperpigmentation and strengthens the skin barrier (Correct answer)
- It functions as an occlusive to seal moisture into the skin
Correct answer: It helps reduce hyperpigmentation and strengthens the skin barrier
Niacinamide inhibits the transfer of melanosomes to keratinocytes, reducing hyperpigmentation. It also increases ceramide production, reinforcing the skin barrier and reducing trans-epidermal water loss (TEWL).
Question 6: In cosmetic chemistry, what does the term 'non-comedogenic' indicate about a product?
- The product contains no synthetic fragrances
- The product is formulated to not clog pores or promote acne formation (Correct answer)
- The product has been tested and is free of allergens
- The product does not contain any chemical preservatives
Correct answer: The product is formulated to not clog pores or promote acne formation
Non-comedogenic products are formulated with ingredients that have low comedogenicity ratings, meaning they are unlikely to block follicles and trigger the formation of comedones (blackheads and whiteheads).
Esthetician Practice Exam Esthetician Practice Cosmetic Chemistry and Ingredients 1
Which pH range is considered optimal for most facial cleansers to maintain the skin's acid mantle?