What actually goes off
Silicone and acrylic sealants have a genuine shelf life — typically twelve to eighteen months from manufacture, printed as a batch date on the cartridge rather than a use-by. Past it they cure slowly, badly or not at all, and a failed bathroom seal is a much bigger problem than a wasted cartridge.
Expanding foam is worse. The canister is pressurised and the propellant degrades; an old can either fails to dispense or discharges unpredictably. Once opened, the nozzle cures solid and the can is generally finished regardless of what remains inside.
Solvents are the exception — white spirit, methylated spirit and acetone keep indefinitely in a sealed container. If the container has degraded, though, that is a different matter, and a rusting tin of thinners is a hazard rather than a resource.
- Sealants: 12–18 months from manufacture
- Expanding foam: 12 months, less once opened
- Adhesives: skin over and won't recover
- Fillers: set hard in the tub
- Solvents: essentially indefinite if sealed
- Check the batch date, not the purchase date
Storing them without creating a fire risk
Solvents, contact adhesives, thinners and aerosols are flammable, and vapour is the actual risk rather than the liquid. Vapour pools at low level and travels, so a shelf of solvents near a boiler pilot light, a freezer motor or a garage consumer unit is a real hazard rather than a theoretical one.
Store them cool, dry, ventilated and off the floor, in original labelled containers with lids tight. An outbuilding or a ventilated garage is better than under the kitchen sink, and better still is a metal cabinet.
Keep aerosols out of direct sun and away from anything warm. A pressurised can in a hot greenhouse or the back of a car in August is the classic domestic aerosol failure.
Workshop shelf finally being cleared?
Cured tubes come with us, liquids go to the tip — we'll sort which is which.
Disposal, by type
Liquid solvents, thinners and unset adhesives go to a recycling centre that takes household hazardous waste. All four Glasgow sites do, free, for residents with proof of address. Never down a drain — a great many outside gullies discharge to surface water.
Fully cured material is different and much simpler. A tube of sealant that has set solid, a tub of filler gone hard, a cured lump of expanding foam — these are inert (the heavy stuff — rubble, concrete, brick and soil) and go in general waste. The distinction is liquid versus solid, exactly as it is with paint.
Aerosols with contents remaining are hazardous waste; genuinely empty ones go in household recycling in most Scottish council areas. Never puncture one to check. The full picture across categories is in our hazardous materials guide.
If it came from a job
Waste from paid work at a property belongs to the contractor, not the householder — so a joiner's leftover adhesives and sealants are trade waste, and household recycling centres will refuse them.
For a trade, hazardous streams need proper documentation rather than a simple transfer note, and they should not be mixed into a general skip or load. Segregating them at the van rather than at the tip is the practical habit.
The wider obligations are in our waste guidance for builders, and general site waste is builders waste removal.
