Washington Esthetician State Board Practice Exam 2026 – Complete Prep Resource

Describing an oil as "biologically inert" indicates that the oil does not react with the biological processes or chemical functions of the skin. This quality suggests that the oil will not interfere with the natural biochemical activities in the skin, such as hydration, cell turnover, or barrier function. Biologically inert oils typically do not provoke a reaction, making them suitable for individuals with sensitive skin or allergies. These oils can serve as emollients or occlusives without altering the skin's environment or chemistry.

In contrast, options that suggest reactions on the skin or high acidity imply active engagement with the skin's processes, which conflicts with the idea of being biologically inert. Additionally, the notion of accelerating skin absorption refers to oils that may enhance the penetration of other substances, while a biologically inert oil would not possess such properties, as it is non-reactive by nature. Thus, the definition of being biologically inert firmly aligns with the notion that the oil does not interact with the skin's functions.