Makeup can separate for a variety of reasons, including improper storage, changes in temperature, and the expiration of the product.

One common reason for makeup separation is improper storage. Makeup products should be stored in a cool, dry place away from direct sunlight. Exposure to heat and humidity can cause makeup products to separate or become less stable. Similarly, makeup products should not be stored in the bathroom, as the humidity and heat from showers and baths can affect their stability.

Temperature changes can also cause makeup to separate. For example, if a makeup product is exposed to extreme cold or heat, it may become less stable and begin to separate. This can occur if a makeup product is left in a hot car or if it is frozen and then thawed.

Another reason for makeup separation is the expiration of the product. Most makeup products have a shelf life of about two years, after which they may begin to separate or become less effective. It is important to check the expiration date of makeup products and discard them when they expire.

To prevent makeup separation, it is important to store makeup products in a cool, dry place away from direct sunlight, avoid exposing them to extreme temperature changes, and discard them when they expire.

In summary, makeup can separate for a variety of reasons, including improper storage, changes in temperature, and the expiration of the product. To prevent makeup separation, it is important to store makeup products properly, avoid exposing them to extreme temperature changes, and discard them when they expire.