Can you use old paint that has been opened? Paint’s Shelf Life
Water-based acrylic and latex paints can stay good for up to 10 years if never opened and kept from freezing. Leftover paints that have been opened should be closed up tightly, stored in a cool, dry place and used within two years.
How can you tell if paint is bad? Rancid- or Sour-Smelling Paint
After the lid is opened, some paint might have a sharp smell: rancid, foul, or sour. Other paint might smell like mold or mildew. If the smelly paint is applied, the smell may lessen but not disappear. Bacterial growth is the driver behind this smell.
Can old paint still be used? The good news is that if you have an unopened can of paint that has been stored properly, it’s almost guaranteed to still be fine to use. Unopened latex and water-based acrylic paints can last up to 10 years and alkyd and oil-based paints can last up to 15 years.
How long is paint good for once opened? A previously opened can of paint lasts 5 years on average if properly sealed and stored. Old paint shelf life can also vary among different types of paint. In particular, an unopened can of latex or acrylic paint lasts up to 10 years.