1. Check the production date and shelf life on the product package: The production date and shelf life are usually marked on the bottle body or packaging box of liquid foundation, which can be used to judge whether the product is expired.
2. Observe the texture and color of liquid foundation: the expired liquid foundation may appear thinning, layering or color change, and it may be expired if abnormal.
3. Smell its odor: Expired liquid foundation usually emits an unpleasant odor. If liquid foundation has an odor, it is likely to have expired.