How to dispose of spray foam cans depends on whether the can is empty. One-part canned spray foam for gaps and cracks is a pressurized aerosol with flammable propellant and uncured isocyanate foam. An empty can, with the nozzle and straw cured solid, can usually go in the regular trash. A can that still has product and pressure should go to a household hazardous waste drop-off. Two-part spray foam kits have their own instructions and usually require hazardous waste disposal.
Is the can empty?
Shake the can and press the trigger outdoors, pointed at cardboard. If nothing comes out and you hear no hiss, it is likely empty. Cured foam may clog the straw, so a can can seem empty while still holding pressure. If unsure, treat it as partly full.
Empty cans
- Let any foam on the nozzle and straw cure fully.
- Leave the cap or straw on.
- Put it in the trash.
Some areas accept empty aerosol steel cans in recycling; spray foam cans are often excluded because of foam residue. Check local rules. See how to dispose of aerosol cans.
Partly full cans
| Option | Notes |
|---|---|
| Household hazardous waste drop-off | Best choice |
| Use it up | Fill gaps, or spray into a box to cure, outdoors |
| Store for later | Many cans can be reused within a short time if the nozzle is cleaned |
Never puncture, crush, or burn a pressurized can. It can burst or ignite.
Two-part spray foam kits
Two-part kits use separate tanks of chemicals that react when mixed. Leftover chemicals, especially the “A” side containing isocyanates, are hazardous. Follow the manufacturer’s disposal instructions, which often say to spray out remaining material into a container to cure or take tanks to hazardous waste.
Cured foam
Cured foam scraps, trimmed overspray, and foam-filled cardboard are solid and go in the trash or construction debris. Rigid foam board is separate; see disposing of rigid foam board.
Storage safety
Store cans upright in a cool place, away from heat or flames, and out of a hot car. Cans can burst at high temperatures.
Gun-style cans
Pro foam guns screw onto cans and can keep a can sealed for later use. Clean the gun with the recommended cleaner, which is also flammable and may need hazardous waste disposal.
How to dispose of spray foam cans FAQ
Can I throw away an empty spray foam can?
Usually yes, once the foam on the nozzle has cured.
Are spray foam cans hazardous waste?
Partly full cans are flammable and pressurized, so many areas treat them as hazardous waste.
Can spray foam cans be recycled?
Often not, because of foam residue. Check local rules.
How do I empty a spray foam can?
Spray remaining foam into a cardboard box outdoors and let it cure.
What do I do with leftover two-part spray foam?
Follow the manufacturer’s instructions; many require hazardous waste disposal.
The bottom line
How to dispose of spray foam cans: trash empty, cured cans; take partly full or pressurized cans to household hazardous waste; never puncture or burn them; and follow manufacturer instructions for two-part kits. Use the map to find a household hazardous waste drop-off near you.
Guides and tools
Household hazardous waste guide · Dump cost calculator · All material guides