Introduction to masks and respirators

Let's unpick what we mean by masks, filters, respirators and understand all the weird accessories.

Meredith in a typical surgical mask. Great for Hollywood, sometimes OK for dealing with coronavirus patients (check with your local authority - NHS guidance here).

There are basically two different things we're dealing with, disposable masks and respirators. They do the same job - keep virusey gunk out of our airways. But handling, buying, and keeping them sterile, are different.

Tom made two videos about the anatomy of disposable masks and respirators (also see them embedded below).

Procedures for putting on and taking off masks

Procedures for Donning (putting on) and Doffing (taking off) masks are important, to keep yourself and the patient free of contamination.

We don't want to risk writing the wrong (or a not locally approved) procedure here, but the NHS in the UK has published an excellent set of guides.

Filter Types

Note: If you're unsure of what type of filter is appropriate (which can vary depending on procedure), always check with your employer or your country's Public Health Authority. Guidance for the UK can be found here.

Both disposable masks and respirators can have different filter types - such as:

  • Surgical and FFP1 (sometimes just P1) which both provide droplet and particle protection to a certain standard. These masks in particular don't necessarily form an air seal to the face (you'll notice that P1 masks don;t have valves), so provide minimal protection against aerosols or airborne contaminant.

  • FFP2, providing an improved standard of particle filtration and aerosol protection than FFP1.

  • FFP3/P3 which provides a high level of particulate and aerosol protection.

  • N95 which is the US equivalent of European FFP2 grade, according to Lee et al 2016 and higher protection level masks (N99, etc).

Do I need FFP3 masks?

At present, FFP3 masks and equivalent are in greatest demand and greatest shortage.

The UK's NHS notes that the filter grade and mask type required depends on the type of procedure you're undertaking, so in some circumstances, Surgical or P1 masks are acceptable - please see their latest documents for guidance.

Note: 'FFP' stands for 'Filtering Face Piece' and is usually attached to disposable masks - an equivalent respirator grade is usually labeled simply 'P3'.

*Sources: https://doi.org/10.1155/2016/8572493 and https://www.gov.uk/government/publications/wuhan-novel-coronavirus-infection-prevention-and-control

Disposable Masks


The basics

Here's a video on the basics of disposable masks - jargon, anatomy, the materials they're made of and some considerations if you're attempting to sterilise these (usually disposable) masks.

Coming Soon - a text and diagrams version of the video...

Sterilisation for reuse

If you can't get disposable masks, consider buying respirators, which are intended for reuse, and for which a sterilisation procedure has been developed and tested.

Things are getting really crazy out there so we may yet end up suggesting procedures for sterilisation and re-use of disposables. We're looking into it (as I'm sure others are), and the video above contains a lot of notes about things to consider. But it'll be in the hands of your country's Public Health Authority as to whether this will be permitted. We'll keep you updated if we hear more.

Respirators


Here's a video on the basics of respirators - jargon, anatomy, the materials they're made of and some considerations if you're using them daily for a long period of time.

Respirators look super sinister. ...Or like alien invaders. Either way, not good for patient fear levels. To help with this, paint a funny face on it. Or put stickers on (ones that will withstand the sterilisation). Please don't cover the valve or filters! You can also talk to your patients about it - verbal reassurance that they need not be afraid will go a long way.
Respirators muffle your voice. This can make communication with patients hard - especially with those who are hard of hearing. Be aware to keep your voice raised and clear whilst communicating.

Coming Soon - a text and diagrams version of the video...

Upgrading

Filter cartridges for respirators can be upgraded, with additional filter pads and 'retainers' to clip them on. Check out the video above for more discussion on how to do this.

Sterilisation for reuse

Respirators are intended to be reused. Manufacturers usually provide guidelines for the appropriate procedure to sterilise masks, such as these from 3M. However...

It's been found that manufacturer's instructions are often not clear enough, resulting in user error.

We found a thorough and peer-reviewed procedure for sterilisation from Bessesen et al 2015, which minimises risk of errors in disinfecting masks.

Your Public Health Authority may also supply such a procedure, in which case you can best protect yourself by using that in preference to our links above.