Is it okay to store cosmetics in the refrigerator?

As the weather gets warmer, many people put their cosmetics in the refrigerator. Is keeping cosmetics cold to prepare for rising temperatures really a good idea?

It is best not to store cosmetics in the refrigerator.

Depending on the type, some products may be refrigerated; lightweight formulations such as toners and gel creams, as well as sheet masks, can be stored in the refrigerator. However, functional cosmetics, oils, and sunscreens should not be refrigerated. Functional cosmetics, in particular, that aid in whitening or wrinkle improvement, or contain vitamins and herbal ingredients, are sensitive to temperature changes. Since functional cosmetics often contain many natural substances or vitamins that easily oxidize or become rancid due to light or air, it is best to store them in a cool place away from direct sunlight. The temperature must also be consistent. The optimal temperature is around 12 to 15 degrees Celsius. However, the average temperature inside a refrigerator is about 5 degrees Celsius, which is significantly different from the optimal temperature. Repeatedly putting cosmetics in and taking them out of the refrigerator causes severe temperature fluctuations. If the temperature is too low, the product is more prone to spoilage, as oil and water separate and frost forms. Even if the product does not spoil, the formulation hardens, reducing its absorption rate. Furthermore, the severe temperature changes caused by repeated refrigeration, combined with the storage of other food items, can lead to bacterial growth.