An extinguisher is a pressure vessel containing a chemical agent, which puts it outside every ordinary waste route. It cannot go in a household bin, it will usually be refused at a household waste site unless they have a specific arrangement, and a business disposing of one is disposing of controlled waste with the duty of care that carries.
Do extinguishers expire
They do not carry a food style expiry date, but they do have a service life, and the British Standard regime brings them out of service through extended servicing and eventual condemnation rather than at a printed date. In practice an extinguisher is retired when a service finds it out of specification, when the cylinder fails its pressure testing regime, or when it reaches the manufacturer's stated life.
Recharge or replace
A discharged extinguisher in good condition is normally recharged rather than replaced, and that is both cheaper and better environmentally. An extinguisher that has corroded, whose cylinder has failed testing, or whose agent has been superseded is replaced. For small domestic units the economics usually favour replacement, because the recharge cost approaches the price of a new one.
How disposal works
The normal route is through the company that services your extinguishers, who will take the old units away as part of a replacement. Failing that, a licensed waste contractor. For a business this is controlled waste and the duty of care applies: you are responsible for it reaching an authorised person, and you should hold the transfer documentation.
Never do it yourself
Do not discharge an extinguisher to empty it before disposal, do not puncture a cylinder, and do not cut one open. They are pressurised well above atmospheric and the agent is not always something you want released in an enclosed space. Carbon dioxide cylinders in particular are high pressure vessels and are dangerous to tamper with.
Questions people ask about how to dispose of fire extinguisher
Do fire extinguishers have an expiry date?
Not a printed expiry date, but they have a service life and a servicing regime that takes them out of service. A unit is retired when a service condemns it, when the cylinder fails testing, or at the manufacturer's stated life.
Can I put an old extinguisher in the bin?
No. It is a pressure vessel containing a chemical agent. The usual route is back through your servicing company; otherwise a licensed waste contractor.
Is it cheaper to recharge than replace?
For larger commercial extinguishers in good condition, usually yes, and it is better environmentally. For small domestic units the recharge cost often approaches a new one.