Although paint cans typically do not have a printed expiration date, paint does expire. Oil-based paints are good for around 15 years, while latex paints last up to 10 years; however, after a paint can is opened, the paint is only usable for two to four years.
There are numerous factors that shorten the amount of time paint is usable after it is opened. If the paint has ever been mixed with water, there is a strong likelihood that bacteria has settled in the paint, producing mold and mildew. If paint has been frozen and thawed a number of times, its smooth consistency is lost, and it becomes clumpy. Proper storage is essential to ensuring the maximum lifespan of paint. Paint lids need to be securely attached, and paint should not be exposed to temperatures below 50 degrees Fahrenheit.