The chemical substance spread on the skin to dissolve the hair at the surface of the skin is called a(n) _________.

• A. Exfoliant
• B. Depilatory
• C. Emollient
• D. Keratolytic

Answer: (B)

Depilatory is used for hair removal by dissolving the hair at or just under the surface of the skin. These agents, often containing thioglycolates, break the disulfide bonds in keratin that give hair its strength. Once these bonds are disrupted, the hair weakens and can be wiped away, leaving the skin smooth. This differs from an exfoliant, which removes dead skin cells without aiming to remove hair; an emollient, which softens and moisturizes skin; and a keratolytic, which loosens thickened keratin in the skin itself, not hair.