Milady Esthetics State Board Practice Test

Which of the following defines a hydrophilic substance?

1. It repels water

2. It attracts water

3. It is unaffected by water

4. It can dissolve in oil

The correct answer is: It attracts water

A hydrophilic substance is defined by its ability to attract water molecules. This characteristic is due to the presence of polar molecules or ionic groups within the hydrophilic substance that can form hydrogen bonds or interact with water, allowing it to easily blend or mix with water. Understanding hydrophilic substances is particularly important in esthetics, as many skincare products contain ingredients designed to hydrate the skin by attracting moisture from the environment or delivering moisture directly to the skin. This property is essential when formulating products meant for skin hydration, as hydrophilic ingredients can enhance the effectiveness of such formulations. In contrast, substances that repel water or are unaffected by it fall into the categories of hydrophobic (repelling water) and non-polar, respectively, which do not effectively mix with water. Additionally, substances that can dissolve in oil are typically lipophilic, which is the opposite of hydrophilic, indicating yet another fundamental distinction that aids in understanding product formulation in the esthetics field.