Air purifiers have never been so popular.

Between the summer of bushfires and now the COVID-19 pandemic, internet searches and retail inquiries for the appliance have never been so high.

Retailers jumped on board the craze, heavily promoting purifiers as a must-have device to keep your family and household safe and healthy.

But do they actually work?

Well, kind of.

Consumer advocate body Choice had a look.

Its investigations revealed a big discrepancy between the good and the bad.

Choice household expert Chris Barnes explained: “An air purifier with a HEPA filter can be surprisingly good at trapping viruses and bacteria out of the air. The issue is that it can only process what’s in the air that it happened to suck in at the time.”

So what does that mean?

It means the best way to keep your household safe from the coronavirus is to practise good hygiene.

That means washing your hands thoroughly, and regularly cleaning high-traffic household areas.

Purifiers can work – and can also just not

Choice’s investigations discovered the most important part about choosing a purifier was to make sure you didn’t choose a dud one.

Mr Barnes said he set out sceptical about the benefits of purifiers, but was surprised that they can help clear bushfire smoke from homes, and can be particularly useful for people with allergies.

“Regarding COVID-19 and other germs, an air purifier might help, but it’s not a solution on its own,” Mr Barnes said.

“Your best options are still the same as before: Minimise unnecessary contact, clean any hard surfaces that people often touch, and regularly wash or sanitise your hands.”

The HEPA (high efficiency particulate air) filters have the ability to trap airborne viruses – like the coronavirus – but that doesn’t mean it will be killed.

The virus, even if trapped in the filter, can still survive in the filter for a few hours or even a day.

So if you remove the filter while the virus is still trapped there, alive, it might be released back into the air or even onto your skin.