Which of the following is a common allergen to be aware of in cosmetics?

Fragrance is a common allergen in cosmetics because it can be made up of numerous chemical compounds, some of which may trigger allergic reactions or sensitivities in individuals. Many people are sensitive to specific fragrances, which can lead to skin irritations, rashes, or respiratory issues upon contact. This is particularly relevant for cosmetology professionals to understand, as they may encounter clients who have allergies or sensitivities to certain fragrances, affecting their cosmetic choices and applications.

In contrast, vitamin C, water, and mineral oil are generally considered safe for use in cosmetic products. Vitamin C, while it can cause irritation in some individuals with very sensitive skin when applied topically, is not commonly recognized as a major allergen across the population. Water is an essential and non-reactive component in cosmetics that serves as a solvent and is not an allergen. Mineral oil is also usually hypoallergenic and is often used to create a barrier on the skin, providing hydration without causing allergic reactions in the majority of users. Thus, while all components of cosmetics should be assessed for individual sensitivities, fragrance stands out as a notable allergen that requires careful consideration in cosmetic formulations and applications.