Behind the Mask

As the country prepares to begin a phased return to work, I am seeing a lot of questions arise around the use of face masks and respiratory protective equipment in particular, so I thought I would write a quick primer on how to use a face mask and when it might be useful.

Defining the Risk As you will know by now, Covid-19 is a new strain of a virus called a Coronavirus. It is not named after the beer, but after the fact that it has spiky protrusions on its surface which allow it to break into and infect cells. On a microscope, these give the virus the appearance of a crown, hence “Corona” virus. (Corona is the Latin word for crown) . The Coronavirus particle itself is tiny – in the order of one hundred millionths of a millimetre across – but comparable to the range of dust particles that FFP2 and FFP3 rated face masks are rated for. It is unusual, however to find a coronavirus particle floating around in the air on its own. The highest risk of transmission comes from what is called “droplet infection” – that is, the virus gets trapped in the microscopic water droplets which we all breathe out all the time, and gets transmitted out of your body in them. The amount of virus in a droplet obviously related to the size of the droplets. In normal breathing, these droplets are tiny, but when we cough of sneeze, they can be full size drops. When the droplet comes into contact with our eyes or nasal membranes, the coronavirus inside it can enter our bloodstream and infect us.
How Should I Use a Mask? Masks of an appropriate rating can help to trap these droplets and reduce the risk of them infecting an unsuspecting nose and lungs, but it’s important to note that they are not a perfect protection. In fact they are a specialist tool and, like any tool, need to be used correctly to ensure they can work properly. Masks rely on the formation of a tight seal around your face in order to work – the filter material is useless if air can go around it through a poor seal, and so the most important thing is to make sure that they fit. For men, this means having a good shave to make sure there is no stubble to interfere with the seal. It is very important that users are tested frequently for a good face fit, and the video below explains what to look out for when putting on a mask.

When Should I Use a Mask?

Masks can be uncomfortable and compliance can be an issue – workers often skip wearing a mask or forget to pick one up, and sometimes may think that wearing a mask is, in and of itself, enough to protect them, even if they wear it incorrectly. In general, PPE should be the last line of defence against a hazard, not the first.

Current government guidance is that a face covering should be worn in enclosed spaces, where social distancing is not possible – that is, if all other measures are not possible, then wear a face covering. Evidence is that a face covering does not protect you, but may help protect others with whom you come into close contact in the event that you are infected but have not yet developed symptoms. The government also makes clear that it sees a distinction between face coverings and surgical masks or respirators, which may provide a higher level of protection, but should be reserved for those who really need them in a healthcare setting or for those exposed to dust or chemical hazards at work due to shortage problems at the moment.

In Summary

  • Face masks can protect you from coronavirus in some situations.

  • They are only useful if used correctly.

  • They are currently a scarce resource, and should only be used as a last resort, where all other avenues to prevent risk are not practical.

  • If using a face mask, take care to make sure the fit is snug, but comfortable.

  • Replace the face mask regularly, and dispose of it if it becomes sweaty, or dirty, or if you have any issues with the seal on your face.

  • Do not touch the face mask while it is on your face, and take extra care when putting on and taking off your face mask. – the WHO gives guidelines here:

Further Reading

As always, don’t hesitate to get in touch if you want to discuss these aspects further. The HSE has good guidance on routing use of respirators, and specific guidance on use for healthcare workers, and the WHO has a series of videos to support the use of masks by the public. Links below: