Amid the ongoing COVID-19 pandemic we are all trying to do our best to protect ourselves and the people around us from the infection. Wearing a surgical mask is good enough for protection, but some experts say that FFP2 and N95 masks, when worn correctly, are significantly more effective.

And yet these masks, which are classified as particulate respirators, will only deliver the promised filtering performance if they are a proper fit. So how are you supposed to know if it's working right?

The first thing to look for: Does the mask get sucked towards your face when you breathe in? This is a sign that no air is able to sneak in around the edges, where the mask touches your face.

If you feel any rapid flow of air on your cheeks, chin or nose, then the mask doesn't fit your face or you haven't put it on properly, says Peter Paszkiewicz, from a German institute for occupational health and safety.

Unfortunately, facial hair and scars can often get in the way of the necessary snug fit and reduce the protective effect. The only solution here is to shave or try a different mask shape.

To check that no air is leaking out the sides, wash your hands and hold them over the edges of the mask. Then try to create pressure by breathing in and out sharply.

If you feel air flowing in or out where the mask meets your face or over the nose clip, then you're not protected.

With a perfect fit, a new and clean FFP2 mask will filter out at least 94% of aerosols from the air you breathe in. FFP is the European standard for particulate respirators, similar to the U.S. standard of N95, which filters out 95% of aerosols.

Still, virologists stress that maintaining proper social distancing and airing out rooms remain vital, even if you're correctly wearing an FFP2 the whole time.

When putting on and taking off the mask, remember not to touch the rim or the inside. If you plan on reusing the mask, hang it up so that as much air as possible gets into the mask and that nothing is touching it.