There are two types of fire extinguishers: rechargeable and disposable. As the name suggests, a disposable fire extinguisher is one which must be thrown away once it's empty. A rechargeable fire extinguisher, on the other hand, can be refilled with its agent (usually water, dry powder, CO2, AFFF foam, or a vapourising liquid) when it's empty. Many owners of rechargeable fire extinguishers get confused by the prospect of replacement: is it necessary, and if so, when? While rechargeable extinguishers can last for a long time, the reality is that there are situations where it needs to be replaced with a new unit. Here's what you need to know about when to keep and service your extinguisher and when to replace it.

Don't Replace When It's Empty

There's no need to dispose of or replace a rechargeable fire extinguisher when it's empty. All you need to do is call in an experienced fire extinguisher services professional to refill the unit. If you're not sure whether your extinguisher is empty, check the gauge needle. If it's in the 'Charge' area, often coloured green, there's no need to have it serviced. If it's in the 'Recharge' area, often coloured red, it will need to be refilled immediately.

Don't Replace When It's Old

Don't replace your fire extinguisher just because it's old. Rechargeable fire extinguishers are made to last for a long time, so they only need to be replaced if they have a fault. Old extinguishers will, however, need to be recharged every decade according to National Fire Protection Standards, even if they've not been used. This is due to natural deterioration of the extinguishing agent.

Do Replace When It's Corroded

Fire extinguishers can corrode for a variety of reasons, often related to the materials used in their construction, and whether the agents inside them have corrosive properties. If an extinguisher becomes corroded, particularly at the stem, it can break or fail when it's most needed. As a result, it's best to have a fire extinguisher replaced if corrosion occurs. Your extinguisher should be checked by a services company for corrosion  at least annually, though many prefer to have them checked twice annually for peace of mind.

Do Replace When Parts are Missing or Broken

The main body of an extinguisher (also known as the cylinder or container) will usually be fairly hardy and resistant to wear and tear. In particularly, the locking pin, the hose, and the nozzle can become loose, get broken, or even go missing. In this case, you usually have two options. A service company may be able to repair your extinguisher using replacement parts. Alternatively, some choose to get their whole extinguisher replaced when parts break or go missing to ensure that full functionality is maintained. Click here to continue reading about fire extinguishers.