1. Skin irritation and allergic reaction: after the expiration of liquid foundation, the chemical composition may change, causing bacteria to breed. When these expired products come into contact with the skin, they may cause allergic reactions such as redness, itching, and stinging, and in severe cases, may also lead to skin inflammation.
2. Blocking pores, causing skin problems: grease and pigment particles in expired liquid foundation may deteriorate, which is more likely to block pores. Long term use of expired liquid foundation will lead to large pores, increased blackheads and acne, and may even cause skin problems such as acne.
3. Reduce the effect of sunscreen and concealer: The sunscreen and concealer ingredients in liquid foundation may become invalid after expiration, and cannot provide adequate protection for the skin. This will not only reduce the concealer ability of liquid foundation, but also make the skin more vulnerable to UV damage and accelerate skin aging.