Texas Cosmetology Operator Written ExamChemistryMedium
A cosmetologist is using a product that lists 'sodium lauryl sulfate' as its primary cleansing agent. Based on its chemical function, what type of ingredient is sodium lauryl sulfate?
- AHumectant
- BEmollient
- CSurfactant
- DPreservative
Show answer & explanationAnswer & explanation
Correct answer: C. Surfactant
Sodium lauryl sulfate (SLS) is a common surfactant. Surfactants are agents that lower the surface tension between two liquids or between a liquid and a solid, making them effective cleansing and foaming agents.
Why the other options are wrong
- A. Humectants attract and hold moisture from the air to the skin or hair.
- B. Emollients soften and smooth the skin, forming a protective barrier.
- D. Preservatives prevent microbial growth and spoilage in cosmetic products.
Surfactant
A substance that lowers the surface tension of a liquid, allowing for easier spreading and wetting, often used as detergents, emulsifiers, foaming agents, and dispersants.
- Reduces surface tension
- Commonly found in cleansers and shampoos
- Can be anionic, cationic, nonionic, or amphoteric
Memory trick: Surfactants Surface for Suds and Spread.