Paint can be a budget-friendly option for touch-ups and home projects, but knowing when it goes bad is key. Unopened paint stays fresh for 10 to 15 years, whereas opened cans can spoil within a couple of years. Expired paint often shows signs like odd textures or bad smells.
Being aware of the shelf life of various paints and proper storage techniques can help keep them usable for longer.
How Long Does Paint Last?
Most paints last one to two years in an open can. Latex paints can last an average of 10 years in an unopened can. Oil-based paint lasts up to 15 years in an unopened can.
The paint goes bad by hardening or becoming rancid when air or debris gets into a can that isn’t sealed well. A can of paint can go bad if it is not stored properly in a cool, dry place as temperatures can play havoc with the consistency and even the smell.
Average Lifespan of Common Paint Types
- Oil-Based Paint
Oil-based paint lasts up to 15 years in an unopened, sealed can or up to 10 years after opening the can if it’s properly sealed. - Acrylic Paint
Acrylic paint can last up to 10 years in an unopened, sealed can, assuming it’s kept in a cool, dark, dry place. It will generally last up to two years after opening the can and only if properly sealed, though some experts estimate it can last up to a decade. - Water-Based Latex Paint
Water-based latex paint could last between two and 10 years. PPG, the manufacturer of PPG Paints and Glidden Paints, estimates that an unopened can of latex paint lasts two years before going bad.1 Sherwin-Williams estimates paint shelf life to be one year for some paints. Behr notes that its interior latex paint’s shelf life is “years.” However, the consensus among experts is that unopened latex paint has a shelf life of 10 years. - Limewash Paint
Limewash paint lasts for 5 to 10 years, possibly even longer if it’s unopened. Because it’s only made of lime, water, and pigment, it’s a simple solution that doesn’t easily go bad. - Chalk Paint
Chalk paint lasts one year according to Annie Sloan, the paint manufacturer. However, the company notes that it can “potentially last for several years.” Chalk paint does not film over like latex paint but will develop a thicker consistency. Revive thickened older chalk paint with water. - Milk Paint
Mixed milk paint lasts only a day or two because it contains milk proteins. If refrigerated, milk paint may last up to a week. Some milk paints have additives that preserve them longer. Dried powdered milk paint can last indefinitely if kept in a dry, cool place.
How to Tell if Paint Is Bad
Several signs clearly indicate that the paint has gone bad:
Rancid- or Sour-Smelling Paint
After the lid is opened, some paint might have a sharp, rancid, sour smell. Other paint might smell like mold or mildew. If the smelly paint is applied, the odor may lessen but not disappear. Bacterial growth is the driver behind this smell.
Paint Has Been Repeatedly Frozen and Thawed
While you should try to prevent your mixed paint from freezing, one manufacturer, Glidden, states that frozen paint can be successfully thawed and used, as long as it is not clumpy and does not exhibit a foul odor. Paint experts, though, tend to agree that repeated freeze-thaw cycles will eventually break down paint.
Overly Lumpy Paint
It is natural for latex paint to develop a film on the top after some time. But if the paint has solidified past the point of a thin film, it is time to discard it. Solidified paint chunks cannot be dissolved by adding water.
Jelly-Like Consistency
One indication that paint is past its prime is when it is entirely or partially jelly-like: neither solid nor liquid but an in-between goopy substance that refuses to mix smoothly.
Try adding water to latex and water-based paint to thin it out. Add paint thinner to oil-based paint to improve the consistency.
Rust on the Paint Can
Spotting rust on the outside of the can may not always mean the paint is bad. However, toss it out if the rust has contaminated the paint inside. Rusty paint stains a surface. When opening a rusty can, be careful that the flakes of rust do not fall into the can because of the slim chance the paint is still good to use.
Mold or Mildew
If the paint can was not properly sealed, mold or mildew may have found its way inside. Do not use any paint with mold or mildew growth. Properly dispose of the paint can at a hazardous waste facility.