What does pH actually measure?
- The percentage of oil in a cream or lotion
- The concentration of hydrogen ions in a water-based solution
- The amount of active ingredient in a product
- The temperature at which a product becomes unstable
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B. The concentration of hydrogen ions in a water-based solution
pH stands for potential hydrogen and expresses how acidic or alkaline a water-containing solution is. Products with no water, such as pure oils, have no pH.
Reference: Product chemistry: pH
What do surfactants do in a cleanser?
- Attract water from the air into the stratum corneum
- Stop bacteria and mold from growing in the product
- Reflect ultraviolet light away from the skin surface
- Lower surface tension so oil and dirt can be lifted and rinsed away
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D. Lower surface tension so oil and dirt can be lifted and rinsed away
Surfactants have a water-loving end and an oil-loving end, which lets them loosen oil and debris so water can carry it off. Attracting water describes humectants.
Reference: Product chemistry: surfactants
Glycerin is used in moisturizers mainly as which type of ingredient?
- Humectant
- Exfoliant
- Preservative
- Sunscreen
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A. Humectant
Humectants such as glycerin attract and hold water in the outer skin. It does not remove cells, preserve the product or filter UV.
Reference: Product chemistry: humectants