How do I dispose of leftover adhesive, sealant and filler?

The rules that matter are simple and the reasoning behind them is worth understanding, because it tells you what to do with a product not on any list. Cured material is a solid and behaves like one. Liquid solvent is mobile, flammable and toxic to water life. And a pressurised can is a small bomb in a compaction lorry.

Safety

Step by step

1. Let anything that can cure, cure.A part-used tube of sealant or adhesive left with the cap off in a ventilated place will harden in days. Cured sealant, cured adhesive and set filler are inert solids and go in general waste. This converts most of the problem into ordinary rubbish.
2. Harden water-based leftovers rather than pouring them.PVA, ready-mixed filler and acrylic caulk can be spread thinly on card or mixed with sawdust, sand or cat litter and left to dry solid. Bin the solid. Never rinse them into a sink, where they set in the trap.
3. Take liquid solvent-based products to the recycling centre.Solvent cement, contact adhesive, uncured resin, hardener, and any adhesive with a flame or health-hazard pictogram on it goes in the hazardous or chemical waste stream. Every household waste recycling centre in the UK takes household chemicals, usually free, and most ask you to book.
4. Take aerosols and foam cans to the recycling centre too.Expanding foam cans and spray adhesive cans hold propellant even when apparently empty. Councils normally have an aerosol point. Never puncture, crush or bin them, and never burn them.
5. Check whether an empty cartridge can be recycled.Rules vary widely by council. Some accept clean rigid plastic cartridges in kerbside recycling, most do not because of the residue. Check your council's list rather than guessing, since wish-cycling contaminates the batch.
6. Keep two-part products separate until disposal.Do not mix leftover epoxy resin and hardener in bulk to solidify them. A large mass generates a great deal of heat as it cures, enough to smoke, scorch a surface or start a fire. Mix only in thin layers, or take both parts in as they are.
7. Bag sharp and contaminated waste.Cured sealant strings, cartridge nozzles, mixing sticks and used gloves go in a bag rather than loose, so that whoever handles the bin does not meet them unexpectedly.
8. Give away what is still good.A part-used cartridge, a nearly full tin of solvent cement or a tub of filler is worth something to a neighbour, a community repair café, a men's shed or a local reuse group. Disposal is the last option, not the first.

Tips

• Most councils require you to book a slot at the household waste recycling centre and some restrict chemical waste to certain sites. Check before you drive.
• Trade quantities are not household waste. If you have a professional amount of anything, the site will refuse it and it needs a licensed waste carrier.
• Keep products in their original labelled containers for disposal. An unlabelled container of unknown liquid may be refused, and it is genuinely dangerous for someone else to handle.
• Buying smaller quantities is the cheapest disposal strategy there is, and for anything you use rarely the small tube usually costs less than the waste from a large one.
• Cured expanding foam is a bulky general waste item rather than a hazardous one. It is only the pressurised can that needs special handling.

Common mistakes

• Washing brushes and tools out in the sink — Solvent damages the drainage system and the treatment works, and water-based adhesive sets in the trap. Wipe tools out on paper and let the paper dry before binning it.
• Putting a foam or aerosol can in the wheelie bin — The compaction gear in the lorry ruptures it. Aerosol cans in bin lorries cause fires and injuries every year.
• Mixing a large batch of epoxy to solidify it for disposal — The exothermic reaction in a large mass gets very hot, smokes and can ignite nearby material. Take the two parts in unmixed.
• Pouring anything down an outside drain — Surface water drains often run straight to a watercourse with no treatment at all. This is both harmful and an offence.

Questions people ask